# Does Adding Visual Signifiers in Animated Transitions Improve Interaction Discoverability?

Eva Mackamul, Fanny Chevalier, Géry Casiez, Sylvain Malacria

► To cite this version:

Eva Mackamul, Fanny Chevalier, Géry Casiez, Sylvain Malacria. Does Adding Visual Signifiers in Animated Transitions Improve Interaction Discoverability?. CHI 2025 - ACM Conference on Human Factors in Computing Systems, ACM, Apr 2025, Yokohama, Japan. 10.1145/3706598.3713914. hal-05004363v2

HAL Id: hal-05004363

https://inria.hal.science/hal-05004363v2

Submitted on 28 Mar 2025

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
# Does Adding Visual Signifiers in Animated Transitions Improve Interaction Discoverability?

Eva Mackamul*†

Univ. Lille, Inria, CNRS, Centrale Lille, UMR 9189 CRISTAL
Lille, France

eva.mackamul@inria.fr

Fanny Chevalier

Department of Computer Science and Statistical Sciences,
University of Toronto

Toronto, Canada

fanny@cs.toronto.edu

Géry Casiez‡

Univ. Lille, CNRS, Inria, Centrale Lille, UMR 9189 CRISTAL
Lille, France

gery.casiez@univ-lille.fr

Sylvain Malacria

Univ. Lille, Inria, CNRS, Centrale Lille, UMR 9189 CRISTAL
Lille, France

sylvain.malacria@inria.fr

<figure><img src="image_2.png" /><figcaption>Figure 1: Interaction signifiers are embedded in animated transitions to temporarily expose users to swipe-revealed hidden widgets, or shwidgets, as a means to increase their discoverability. The shwidget interaction is hidden in the application view (middle). A user then swipes an email away from the edge of the touch screen to reveal the hidden buttons.</figcaption></figure>

## Abstract

Smartphones support diverse inputs, however, the multitude of devices and platforms makes it challenging for people to discover when and where interactions are meaningful. Motivated by the effectiveness of visual signifiers in communicating interactivity, we explore the viability of integrating temporary visual signifiers in animated transitions between UI screens to promote the discoverability of swipe-revealed widgets. We implemented two transition types (Container Transform, Panels), and compared them to a baseline. We found that transitions with a standard duration did not impact the discovery of swipe-related widgets (N=33). We ran a follow-up study (N=22) with extremely slow 5000ms transitions to guarantee noticeability, but similarly found no impact on discovery of swipe-revealed widgets, diverging from previous findings for

visual signifiers. This raises interesting questions about the perception and understanding of interaction signifiers, and indicates a disconnect between noticeability and discoverability, while highlighting difficulties with adapting established interface elements beyond their entrenched functionality.

## CCS Concepts

* **Human-centered computing → Interaction techniques; User studies; Touch screens.**

## Keywords

shwidgets, animated transition, interaction signifiers, discoverability

## ACM Reference Format:

Eva Mackamul, Fanny Chevalier, Géry Casiez, and Sylvain Malacria. 2025. Does Adding Visual Signifiers in Animated Transitions Improve Interaction Discoverability?. In *CHI Conference on Human Factors in Computing Systems (CHI '25), April 26-May 1, 2025, Yokohama, Japan*. ACM, New York, NY, USA, 17 pages. https://doi.org/10.1145/3706598.3713914

## 1 Introduction

Touch input, as the primary mode of interaction with smartphones, is now omnipresent. It enables various interactions ranging from

<footnote>*Also with CNRS, Université Grenoble Alpes.</footnote>

<footnote>†Also with Department of Computer Science and Statistical Sciences, University of Toronto.</footnote>

<footnote>‡Also with Institut Universitaire de France.</footnote>
simple taps to gestures like swiping, long press, drag or pinch-and-spread. Many of these interactions are now considered by designers as "core gestures" that users should be familiar with and are expected to "discover on their own" [9]. However, the variety of devices, platforms, and contexts leads to inconsistent interactions, making it hard for users to know *where* and *when* touch gestures are meaningful. For example, although all these chat applications look similar in layout, a *left* swipe archives chats in Telegram (v10.0.5), whereas it is a *right* swipe in Signal (v6.31.2), and both *left* and *right* swipes in Android Messages (Android 13). In Whatsapp (v2.23.17.80), swipes are used for lateral navigation between tabs. These inconsistencies hinder knowledge transfer and interaction discoverability [29, 38, 39].

A common solution for bad discoverability is to use visual signifiers that communicate the availability of interactions [28]. However, clutter is a concern for mobile touch screens offering substantial functionality on limited screen real estate. Some interface components are specifically designed to be out-of-view to reduce clutter, so introducing visual signifiers to support their discovery would negate the benefits. To maintain a clean interface while improving discoverability, hidden interactions should be exposed without adding screen clutter [39].

We investigate one way to achieve this careful balance by incorporating *temporarily-visible* interaction signifiers to existing screen elements, in particular animated transitions. Animated transitions are well established in commercial devices [27] and have been shown to increase the perception of continuity in interfaces [21], establish causal connections between states [44], guide user attention and highlight changes [33], and support accurate mental models of applications [23]. Therefore, leveraging animated transitions as a vessel to increase awareness and understanding of available interface components is a promising approach. Typically, existing visual signifiers are integrated within widgets, by subtly changing their representation to persistently show a static hint or provide animated feedback upon interaction [1, 16–18, 28], or alternatively, transiently triggering a short animation demonstrating the interaction (e.g. Instagram Reels see subsection 2.4). To the best of our knowledge, this study is the first looking at a different conceptual approach: to signify existing widgets by showing their existence during animation between UI screens, without altering their representation. Our work addresses the research question: does extending the function of animated transitions to signify interaction increase discoverability? In particular, we explore the discoverability of swipe-revealed hidden widgets or *Swhidgets* [39] (see Figure 1 right). Swhidgets provide an ideal opportunity to incorporate temporary signifiers in animated transitions because they (1) enrich the set of widgets available to users [41] *without* requiring permanent screen real estate as they are hidden by design, and (2) their positioning conforms to the navigational information that animated transitions have been shown to communicate successfully [23].

To fully explore this potential, we adapt existing animated transitions to temporarily show swhidgets. We integrate visual signifiers into two types of animated transitions based on existing styles and conventions [27]: *Container Transform* and *Panels*. In a controlled experiment (N=33), we evaluate the impact of these animations (with signifiers) compared to a baseline (without signifiers) on the

discoverability of swhidgets when performing simple tasks requiring features available through swhidgets. Diverging from previous findings that visual signifiers improve interaction discoverability, we found no significant impact on the discovery of the swhidgets. Given that some participants explicitly described the transitions and the interaction signifiers embedded in them, this challenges our expectations that noticeability would, in principle, translate to discoverability. To further examine this divergence from the established consensus regarding signifiers, we repeated the experiment with an exaggerated slow duration of 5000ms (N=22), thus guaranteeing noticeability. Despite results showing that *Panels*, which differs more from commercial standards, was successful in signifying the availability of some swhidgets, it failed to do so for unusual implementations, while *Container Transform* failed to improve the discovery of swhidgets in general. Overall, the results of our studies suggest that although temporary visual signifiers in animated transitions are noticeable, they do not consistently translate to comprehension and discoverability. This raises interesting questions about the timing and placement of interaction signifiers as well as the perception of different interface components and users ability to infer interactivity. Aside from participants remarking upon the difficulty of inferring the correct input to access a tool solely through its depiction in the transition, our findings also suggest that the entrenched role associated with established UI elements may preclude them as viable for conveying interactivity.

Our work makes the following contributions. We introduce temporary visual interaction signifiers embedded in animated transitions, which we implement in two types of transitions. We provide empirical results of two studies examining the perception and impact of animated transitions featuring temporary visual interaction signifiers on the discoverability of swhidgets. In doing so, we expose limitations about our understanding of visual interaction signifiers and a disconnect between noticeability and discovery. We discuss possible causes and highlight the difficulty of adapting established UI elements to include interaction signifiers effectively, where users do not expect them. Finally, we show the difficulty of studying interaction discoverability and provide comprehensive methods to do so.

## 2 Related Work

Our work combines the potential of visual signifiers to communicate interaction availability, and that of animated transitions to convey information. We then examine swridget interactions and the characteristics that make them a well-suited vessel to study whether animated transitions can be used to communicate interaction possibilities.

### 2.1 Visual Signifiers

Visual signifiers are interface elements that communicate the availability of interactions [36], by making affordances perceivable through visual cues in the system. Research examples include communication of novel undo mechanisms [1], force-based text selection [18], keyboard shortcuts [17], in-place single finger inputs [28], single handed micro-gestures [24], as well as interaction on digital tabletops [42] and multi-touch displays [30].
Touch screens, which afford various touch inputs [37], require signifiers to communicate which touch input is meaningful in which location and context. This is evidenced by guidelines for designing mobile interfaces, which dedicate entire chapters to visual patterns of interaction and how visualisations communicate context and available interactions [11]. Added visual signifiers used to convey touch-based interaction include visual depictions of scales, metaphorical depictions, or text around a button or touchpoint [16, 18, 28]. They are typically static and displayed permanently or temporary concurrent to the interaction.

In addition, established design patterns to communicate the availability of *swiping* include partially visible content at the view edges, carousels previewing content, tabs and menu bars highlighting the selection of a currently visible view alongside the existence of others to their sides as well as animations telling us to swipe to unlock or open. Signifiers are essential in communicating which type of interaction is available *where* and *when* in the interface.

## 2.2 Animated Transitions

Transitions between UI views describe the switch from view A to view B. To improve usability and navigability, these transitions are usually animated, thereby making the relationship between different views apparent [27, 43]. Animated transitions are well established tools to keep users oriented during navigation and to support tracking during layout changes [3, 8]. As such, they have been found to increase the perception of continuity [21], guide user attention and highlight changes [7, 33], support the formation of accurate mental models [23], and increase the understanding of the causal connection between states [44], on top of being considered visually pleasing [7, 44]. Further, the animation of transitions has been shown to increase user ratings of visual appearance and aid the re-direction of attention [12].

Transitions encompass various design dimensions, including the trajectories that elements follow, the staging, duration, as well as pacing of the animation [43]. For interface design, Apple's developer design guidelines feature vague recommendations like *"design a launch screen that smooths the transition to the first screen"* [14] and to *"avoid jarring transitions"* [13], but do not offer a comprehensive record of the transition types currently implemented in their system. Material Design offers a transitions help guide [27] which examines transitions in both Android and iOS considering different transition patterns and when they are suitable.

These established patterns make it clear that animation has become an essential part of transitions and has successfully been utilised to improve the user experience, which is also reflected in its many roles in interface design [3, 8]. Of particular relevance, is *"Role 5: Providing affordance and preview"* [8], which aids discovery and understanding.

Motivated by the proven success of visual signifiers and animated transitions in conveying information, and the capacity of animations to serve as affordance previews, we explore the potential of incorporating visual signifiers into animated transitions to convey interaction availability and improve discoverability.

## 2.3 Swipe-Revealed HiddenWidgets

Swipe-revealed hidden widgets, or Swidgets, are a technique employed in touch interfaces to provide users access to controls such as buttons and actions through a swipe gesture, while not taking up screen real estate [39]. They are interactive elements that (1) are hidden by default, (2) introduce a new component when revealed through swiping, and (3) do not permanently change the main view of the interface, which often remains consistent "underneath" or "above" the shridget. Pong and Malacria [39] classified three types of shwidgets — system, view, and item (Figure 2).

Swidgets generally perform one or multiple of three functions: revealing information, revealing action items, or executing an action. To do so, they follow a movement pattern in which they are out of view and move with the finger once a swipe in the correct area is performed. On release they either snap to an end position which executes an action or reveals action items, or they move back out of view, depending on whether a threshold is reached.

While swidgets rely on a small set of core principles, they span a rich design space, with dimensions including type of shridget (Figure 2), associated functions (i.e. buttons, actions, ...), as well as how they respond to user input (i.e. trigger action upon release, thresholds, ...). As a result, it is not trivial for users to be aware which swidgets may be available in an interface, nor what their specifics are. This challenge is further exacerbated by the lack of standards and conventions, as existing swidgets are inconsistent across different operating systems and applications. For example, in Whatsapp (v2.23.2.76) swiping *right* on a message allows to 'reply' directly to the message, whereas in Telegram (v9.4.2), which bears a strong resemblance to the Whatsapp interface, swiping *right* returns to the message overview and swiping *left* allows the 'reply' option by default. While Android 13 allows access to a control panel and notifications by swiping from the top of the screen, iOS differentiates between downward swipes from different edges at the top of the screen, revealing notifications or the control panel when swiping from the left- and right-hand corners, respectively.

While other interaction on mobile phones, like gestures or force and double tapping, similarly lack discoverability [28], their touch targets are either clearly established on screen elements or unrestrained. In contrast, swidgets are consistently placed on the screen edges but their discoverability is hindered by their inherent hidden nature. To maintain their value as a powerful tool to augment the range of possible in-context interactions in touch interfaces, their discoverability needs to be improved without adding permanent visualisation. Given this need, as well as their positioning, swidgets present a uniquely suited interaction widget to signify in animated transitions.

## 2.4 Visual Signifiers for Swidgets

Hidden by design, swidgets typically do not provide any visual cues until the swipe gesture is initiated. Nonetheless, there are notable examples of "swipe-ability" being visually communicated for content beyond the screen bounds.

In Instagram Reels (v282.0.0.22.119), the availability of swiping upwards to switch to the next reel is shown through an animation moving the current content upwards, giving a peek at the following reel with overlaid text "Swipe up to see more" (Figure 3 left). Two
<figure><img src="image_3.png" /><figcaption>Figure 2: Visualisations of different swipe-revealed hidden widgets, coloured in green. Other elements from the main view moved with the swipe are coloured in blue. (a) Swipe from the top or bottom of the screen reveals a system shridget, which appears on top of the general view. (b) Swipe from the screen edge moves the majority of the main view to reveal a shridget in the created space. (c) Swipe horizontally on a list item moves the item to reveal a shridget beneath it.</figcaption></figure>

<figure><img src="image_4.png" /><figcaption>Figure 3: Examples of shwidgets being temporarily signified through animation. Left: Instagram Reels animation shows one can swipe up to see more. Middle: iOS alarm ‘edit’ page featuring a swipe animation. Right: Hinge match page showing preview animation of swipe revealed menu when dwelling on the item. Note: original colours edited for emphasis.</figcaption></figure>

other examples signify “swipe-ability” once a shridget is being
interacted with through other means. In iOS 16.3 the *Clock* appli-
cation allows users to delete alarms by swiping on them, as well
as through an edit button that displays "minus" buttons for each
alarm, which then reveal a delete button. In this edit mode, an ani-
mation shows one alarm list item moving to the left, revealing a
red block with ‘Delete’ written on it (Figure 3 middle). Ironically, in
this edit view swiping on alarm items (including the one featured
in the animation) is not possible. Swiping on the alarms is only
possible once users exit the editing mode, that shows them the
theoretical availability of the shridget. In the Hinge application
(v9.25.1) swiping on existing matches in a list view reveals a menu.
The menu options are not accessible through other means, however
when dwelling on one of the matches, a short animation of the
list item moving to the left is shown (Figure 3 right). Since this
animation is temporary and does not fully reveal any option in the
menu, it is purely implemented to signify the possibility of swiping.
Additionally, iOS lock screens feature a horizontal "pull indicator"
in the form of a horizontal line at bottom center and top right of the
screen. In contrast, the Android 13 lock screen shows a bouncing
animation and the text "Swipe up to open" upon repeated tapping.
These examples show the diverse approaches to making shwidgets
more discoverable, while also highlighting that their hidden design
creates the need to signify their availability separately. Nonethe-
less, these approaches for designing visual signifiers for shwidgets
are limited and not generalizable. The Instagram Reels signifier is
dependent on the context of the application and, even within this
context, disrupts the interface design. Moving the entire screen is
not feasible or desirable in most usage contexts. Further, both the
iOS alarm clock and Hinge menu rely on users already recognising
the existence of the function accessible through the shridget, only

showing the animated signifiers in response to other input. This
makes these signifiers unsuitable for novice users.

2.5 Research Gap

Despite the wide adoption of touch based interaction, the discov-
erability of available interactions and hidden elements remains
a challenge [25, 39] limiting their successful or optimised usage.
To address this issue, visual signifiers are used to communicate
affordances [28]. However, permanent signifiers can clutter the
interface and negate the advantages of hidden elements that ought
to be discovered, and minimalist design. Therefore, the inclusion of
temporary visual signifiers embedded in existing screen elements
presents an opportunity to improve discoverability while adhering
to the established design guidelines and aesthetics. In particular,
animated transitions have been shown to support understanding
and navigability in mobile interfaces [23] but their potential to sup-
port the understanding of available affordances has not yet been
explored. Since transitions between UI screens are temporary and
visible as a new UI screen is introduced, they present an exciting
opportunity to clarify possible interactions within the new inter-
face. As subsection 2.3 highlights, swipe-revealed hidden widgets
are inherently hidden and are therefore a prime target for attempts
to improve discoverability. Further, since they are triggered from
the edges of the screen, their location is in line with common an-
imation patterns for transitions, making them uniquely suitable
as an interaction to communicate through signifiers embedded in
transitions.

We propose displaying signifiers only temporarily, as a way
to sustain the clutter-reducing nature of shwidgets, while sub-
tly supporting their discovery. With animated transitions being
omnipresent, the inclusion of temporary signifiers in transitions
presents the potential of significantly improving interaction discov-
erability while utilising existing UI elements to their fullest extent,
which we study in this work.

3 Animated Transitions Integrating Visual Interaction Signifiers

We propose adding visual signifiers to animated transitions to
briefly expose users to shwidgets, while keeping the interface un-
cluttered. Doing so requires minimal changes in current UIs: adding
visual components that show the presence of shwidgets beyond
the usual screen bounds can be achieved while maintaining the
animation style that provides context and help to navigate a system.

Given that a main factor contributing to the lack of discovery
and use of shwidgets is their hidden nature and a subsequent lack of
awareness [39], we create designs that show their presence before
they disappear off screen. In doing so, the implemented signifiers
do not show the interaction in question, which is well established,
but rather provide feedforward by showing the availability of tools
accessible through swiping.

**3.1 Transition Type**

Capitalizing on existing transitions, we lean on established tran-
sition patterns [27] to expand upon and describe two modified
transitions below. Video clips are provided in the supplementary
material and video figure.

*Container Transform* transitions are adapted to include shwidgets beyond the screen bounds early in the transformation, when the outer edges of the shape are still fully visible (Figure 4). The visible shwidgets then move beyond the screen bounds as the container scales up from view A, to transform into the end position at view B.

*Panels* transitions combine *Top Level* and *Enter and Exit* transition patterns to create panels featuring the shwidgets moving out of view. Individually, top level transitions are not suitable to communicate the existence of shwidgets as they do not include motion and immediately arrive at the end state, view B. However, this near instantaneous transition between states A and B allows additional time to be dedicated to temporary interaction signifiers. We implement these by adding the shwidgets, which would typically not be visible in view B, to the initial view loaded through the top level transition and then move them to their location outside the screen bounds through an exit transition (Figure 5).

The transition types were selected following careful consideration
of existing transition patterns and suitability to incorporate addi-
tional visual signifiers. A preliminary study suggested *Panels* to
be the most noticeable transition while *Container Transform* most
closely resembles the native transition style for this context (see
supplementary material), leading to their selection above other
designs. All transitions are designed using a slow-out animation
pacing, which has been found to improve user performance in com-
parison to other pacings [15], and is in line with industry standards
[26].

## 3.2 Transition Duration

Previous work suggests that the minimum duration for conscious
perception is shortly after 200ms [4, 40]. This is in line with cur-
rent conventions for transitions, with Material Design guidelines
suggesting durations between 200ms and 500ms for different tran-
sition types, and offering default values for motion durations up
to 1000ms in their ‘Design tokens’ [26]. This maximum duration
matches the suggestion that for user interface responses, 1000ms
is the maximum time for the user’s flow of thought to stay unin-
terrupted [34]. Following these considerations, pilot testing (see
supplementary material) and the aim for the transitions to be con-
sciously perceived, we implement transitions with a duration of
750ms for our experiment. This achieves a balance between notice-
ability of transitions (slow enough to be meaningfully seen) and a
smooth user experience (fast enough to avoid confusion) compared
to other durations.

4 Study 1 - Impact of Temporary Interaction Signifiers in Transitions on Discoverability

To examine whether interaction signifiers in transitions improve
the discoverability of shwidgets, we ran a user study comparing
*Container Transform* and *Panels* to a *Baseline* transition with no
interaction signifiers embedded.

4.1 Measuring Discoverability

Studying discoverability creates tension between meaningful results
and avoiding discovery caused by the study setup and instructions.
Participants need to interact with the system that implements the
transitions introduced in section 3 without being aware of the aim
of the study, as a clear focus on a type of visualisation (transitions)
or the use of a particular interaction (shwidgets) predisposes partic-
ipants to exploring the availability of said interaction. We therefore
employ decoy TASKS, through which participants encounter the
visualisation and interactivity in question without revealing them
as the focus of the research.

Further, discovery is a binary measure. A shwidget is discovered
or not, and can therefore only be discovered once per participant.
We therefore measure the binary discovery as well as the speed of
discovery for each interaction (SWHIDGET) per participant.

## 4.2 Experimental Design and Procedure

To test the discovery of shwidgets, we created a web application
featuring 6 TASKS (see subsubsection 4.2.1) with 4 different SWHID-
GETS (see subsubsection 4.2.2) that are visually signified in animated
transitions (see subsubsection 4.2.3). <fnref n="1" />

4.2.1 *Tasks.* Similarly to previous work [16], the tasks were selected to mimic real world activities while progressively increasing the need to utilise the interaction whose discoverability we aim to improve. TASKS were accessible from a “homescreen” with 6 numbered buttons. TASKS 1–4 were pictionary tasks, where participants had to draw a given word or phrase, whereas TASKS 5 and 6 were questionnaires in which participants were asked to indicate their agreement/disagreement with a statement. The drawing TASK was

<footnote n="1">¹Sourcecode, images and detailed results for this and subsequent experiments available on OSF https://osf.io/vrhqc/</footnote>
<figure><img src="image_5.png" /><figcaption>Figure 4: Adapted ‘Container Transform’ animation of an email application opening, showing the available swidgets on both sides as the icon scales up.</figcaption></figure>

<figure><img src="image_6.png" /><figcaption>Figure 5: Adapted ‘Combination Top Level + Enter and Exit’ animation of an email application opening, with the application opening instantaneous and the available swidgets slowly sliding out through an exit animation.</figcaption></figure>

selected since it presents a familiar context in which the selection and usage of multiple tools is established. As such it is a common basis for touch-based mobile experiments (e.g.[6, 19, 20, 47]), while not being widely connected to swidgets. In contrast, the rating Task was implemented in a layout that commonly implements swidgets across operating systems but in an adapted context (i.e. rating) to ensure novelty to users regardless of their previous experience.

The design of explicitly novel tasks and contexts was implemented in an effort to ensure that discoverability was not impacted by previous familiarity with specific applications or operating systems.

### 4.2.2 Swidgets.
We integrated 4 SWHIDGETS into the UI. For the pictorialy TASKS (1-4), we made drawing tools available via swiping from the left (Stroke Width, Clear Canvas) or the right (Colour) edge of the screen (Figure 6 left). TASK 4 substantially increases the necessity to use Colour (Right) through the prompt of two drawings that differ solely in colour (French and Belgian Flags), making discovery of the tool menu almost essential to properly complete the task.

For the question TASKS (5+6), participants could indicate their agreement/disagreement with a statement by swiping left or right on the item (Figure 6 right (Rating (Left/Right))). While the first question task (TASK 5) also allowed ratings to be registered through tapping on the item and selecting agree/disagree on a pop-up screen, this option was removed for the final TASK 6, forcing discovery to complete it. Additionally, a SWHIDGET to Submit was implemented across all tasks, triggered by swiping upwards from the bottom edge of the screen. However, tasks could also be closed through

<figure><img src="image_7.png" /><figcaption>Figure 6: SWHIDGETS implemented in the discoverability study for the drawing task (left) and the question tasks (right).</figcaption></figure>

a three-dot menu in the top right corner, which revealed a menu with a sole ‘Submit’ option.

The drawing tool menus (*Stroke (Left)*, *Colour (Right)*) follow a “Snap to end position” pattern, meaning they reveal action items once a translation threshold is reached. In contrast, the *Rating (Left/Right)* and *Submit (Bottom)* SWHIDGETS immediately execute actions when the translation threshold is reached. Importantly, note that from a UI perspective, the *Stroke (Left)*, *Colour (Right)* and *Submit (Bottom)* SWHIDGETS are novel, whereas the *Rating (Left/Right)* SWHIDGET in TASKS 5 and 6 mirrors the behaviour of existing list views such as emails or discussions.
### 4.2.3 *Transitions.* Participants were shown one of three TRANSITION TYPES throughout the experiment: *Container Transform* (Figure 7-middle), *Panels* (Figure 7-bottom) or the baseline (which corresponds to *Container Transform* without the interaction signifiers, as illustrated Figure 7-top). When tapping a task button, the corresponding task opened playing the 750ms transition. Transition animations were created using Adobe After Effects and exported as 60 images per second sequences. We built a web application using PixiJS to load these images and play them back upon tapping a task button.

### 4.2.4 *Procedure.*
The experiment followed the procedure outlined in Figure 8. After first signing consent forms and filling out demographic information, participants were handed an iPhone XS iOS 16.4 running the application opened on the "homescreen" featuring 6 numbered task buttons. They were instructed to complete the tasks to the best of their ability while thinking aloud. The TRANSITION TYPE remained the same for all 6 tasks. Following a split-plot design, each participant experienced one TRANSITION TYPE (section 4.2.3), while all participants completed the same TASKS (section 4.2.1) featuring the same SWHIDGETS (section 4.2.2). A researcher took observational notes, and both the interaction on screen and participants' voice were recorded for further analysis of their experience.

Upon completing the TASKS participants were asked structured questions about their experience. First, participants who used the SWHIDGETS available while completing TASKS 1-5 (i.e. swidgets they were not forced to discover) were asked how they knew they could swipe from the screen edge to reveal additional functions. Participants who had not used the swidgets were asked whether they were aware of them. Afterwards, participants were asked to rate the noticeability of the transition on a 7-point Likert scale (1: Not at all noticeable – 7: Extremely noticeable). Participants were asked to indicate their agreement/disagreement with 4 statements to gauge how they perceived the animated transition, as well as their familiarity with different swidget types (1: Not at all – 7: Extremely high). Finally, following this structured questionnaire, the experimenter asked semi-structured questions following their notes for clarification where participant behaviour or comments throughout the experiment were unclear.

## 4.3 Participants Study 1

We recruited 33 participants via word of mouth. They were aged 23 to 57 (Mean=30.45, SD=7.43) with 22 self-identifying as men, and 11 as women. The research was approved by our institutional ethics review board. None of the participants were previously familiar with the project or transitions, and were not compensated for their participation. Each participant completed the 6 TASKS with one consistent TRANSITION TYPE throughout the TASKS.

## 4.4 Results Study 1

We employ two metrics as indicators of discoverability. First, we use the percentage of participants who used, and therefore discovered a given swidget. Since we present the SWHIDGETS in a novel interface, none of the participants were previously familiar with any of these particular swidgets, meaning usage would necessitate

previous discovery of the interaction opportunity. Second, we measure the time in seconds from the point a swidget was available to participants, to their first use, as a proxy for the amount of time it took at most to discover a given swidget.

### 4.4.1 *Usage/Discovery Percentage and Behaviour.*
We use a chi-squared test since we compare categorical data between three independent groups and want to test a potential impact of one independent variable (TRANSITION TYPE) on a dependent variable (SWHIDGET used/not used). We first analysed cumulative discovery values, using a binary discovered/not discovered metric for participants across all SWHIDGETS and TASKS 1-5. 'Not discovered' means participants didn't use any SWHIDGET in these tasks. No significant difference was found ($\chi^2(2) = 1.06, p = 0.59$), with a power analysis showing our experiment could detect an effect size of 0.54, corresponding to a moderate to large effect [10]. There was no significant difference in the odds of using the swidgets between the *Baseline* and the *TRANSITIONS* featuring signifiers (*Container Transform*, *Panels*) (OR = 0.49, 95% CI [0.01, 41.08]). We also found no significant effect of TRANSITION TYPE ($\chi^2(18) = 15.74, p = 0.61$) across TASKS on SWHIDGET usage (see Figure 9). However, observation of participants revealed interesting patterns.

*Stroke (Left) & Colour (Right) SWHIDGETS.* During task 1-4, 7 participants (2 *Baseline*, 4 *Container Transform*, 1 *Panels*) used none of the available SWHIDGETS. When questioned, all of them indicated that they had not been aware of them. Notably, 11 participants accessed the *Stroke (Left) or Colour (Right) SWHIDGET* in TASK 2 accidentally drawing lines to split the canvas in 4 and, when drawing the horizontal line, swiped from the border opening the *SWHIDGETS*. However, while 7 of them immediately used the newly available tools and explored the interface for further “hidden” interactions, others entirely disregarded their encounter. Two of those participants, later on “discovered” the SWHIDGETS and used them, indicating that their previous disregard was not due to a lack of interest in the available tools, but a focus on first completing the TASK.

*Rating (Left/Right) SWHIDGETS.* Only 7 participants (1 *Baseline*, 3 *Container Transform*, 3 *Panels*) discovered and used the *Rating (Left/Right) SWHIDGET* in TASK 5. This was despite the extra effort required by the alternative method, which was a popup that appeared when tapping the statement that then offered (dis)agree buttons. Moreover, that popup appeared on top of the test, requiring to open and close it repeatedly to read the statement again. Notably, of the participants who did discover the SWHIDGET in TASK 5, none returned to using the popup, indicating that the SWHIDGET was the preferred interaction method after it was discovered. In TASK 6, which forced discovery of the *Rating (Left/Right) SWHIDGET* because the popup was removed, all participants independently discovered the SWHIDGET and completed the task. That said, participants who had not discovered the SWHIDGET in TASK 5, largely attempted other interactions before discovering the availability to swipe in TASK 6. Participants repeatedly attempted to tap, as well as tapping different locations and in specific orders, using force and dwelling. Despite swipe being a common interaction in list views and the majority of participants indicating general familiarity with list view swidgets (section 4.4.3), it was not the first interaction attempt following tap. Notably, one participant, after discovering
<figure><img src="image_8.png" /><figcaption>Figure 7: Animated transitions between the task ‘homescreen’ and the individual tasks. Top depicts the baseline transition animation, a simple scale-up animation that does not include any interaction signifiers. Middle depicts *Container Transform TRANSITION* that includes temporary interaction signifiers at the edges of the container, that move out of view as the end state of the transition is reached. Bottom depicts *Panels TRANSITION* that shows the shwidgets showing up on the edges of the screen as ‘Panels’ before exiting the screen in the direction in which they are accessible.</figcaption></figure>

<figure><img src="image_9.png" /><figcaption>Figure 8: Outline of the procedure and overview of tasks and the shwidgets available for them. Shwidgets in green are necessary to complete the task, but another way to achieve the function is available in the interface. Shwidgets in yellow are not necessary to complete the task but are the only way to access this particular function. Shwidget in orange are necessary to complete the task and the only way to access this particular function. Figure 6 depicts the shwidgets and their position on the screen bounds of the phone.</figcaption></figure>

the SWHIDGET at the end of TASK 5, noted upon seeing the transition: “Oh that’s why there was a slide animation.” [P26 - Panels],

indicating that they had noticed the animation but did not connect it to the shwidget until they had accidentally discovered it.
<figure><img src="image_10.png" /><figcaption>Figure 9: Plot showing the percentage of participants that used a given SWHIDGET per TASK and TRANSITION TYPE. In TASK 1-4 Stroke (Left) and Colour (Right) SWHIDGETS were available, while TASK 5 and 6 included Rating (Left/Right) SWHIDGETS. TASK 6 made the Rating (Left/Right) SWHIDGET necessary to complete the task.</figcaption></figure>

Submit (Bottom) SWHIDGET. The Submit (Bottom) SWHIDGET was only used by three participants, one in each TRANSITION TYPE condition. Multiple participants tried to either 'tap' the bar at the bottom or attempted to swipe up from a wrong position. However, upon questioning their reasoning, it became clear that none of the 10 participants who attempted to swipe up in the wrong position did so to submit the task or because they had noticed the option in the transition. Their reasoning varied from searching for further tools ("I'm looking for an undo, there must be one...." [P26 - Panels]) and testing all swipe directions ("I saw that there was something hidden [left and right] so I tried all [the directions from the screen edge]." [P21 - Container Transform]), to familiarity with the availability of swiping up or a lack of familiarity with the iOS interface in particular ("I didn't know what that [iOS bottom bar] does, so I thought it might be used for that." [P24 - Container Transform]).

4.4.2 Timing. We consider the time until a SWHIDGET was first used from when it was first available to the participant (beginning TASK 1 for Stroke (Left), Colour (Right) and Submit (Bottom) and TASK 4 for Rating (Left/Right)). We use a Kruskal-Wallis test since the data is not normally distributed. If we filter out participants who never used a given swidget, no significant effect of TRANSITION TYPE is observed, for any of the SWHIDGETS (Figure 10a).

For the pictionary tasks, neither the Stroke (Left) (H(2) = 2.45, p = 0.29), nor the Colour (Right) (H(2) = 0.41, p = 0.82) SWHIDGET varied significantly in the time required until the first use of the swidget between TRANSITION TYPES. Similarly, the time until the Rating (Left/Right) SWHIDGET was first used in the question TASKS, did not vary significantly between TRANSITION TYPES (H(2) = 1.15, p = 0.56). The number of data points varies between the different SWHIDGET and TRANSITION TYPES, as some participants did not use all of the SWHIDGET. All participants were forced to discover the Rating (Left/Right) SWHIDGET in the final task, as the only means to complete it. Subsequently, there are not enough data points for the Submit (Bottom) SWHIDGET to provide meaningful insights, as there were only 3 participants (one per TRANSITION TYPE) who discovered the SWHIDGET at all.

To examine the same data including participants who failed to discover and use the SWHIDGET, we use the total completion time for those participants, since it represents the earliest time they could feasibly use the SWHIDGET since they failed to do so

during the experiment (see Figure 10b). With these additions, there was no significant effect of TRANSITION TYPE on the time until Colour (Right) (H(2) = 1.64, p = 0.44), Rating (Left/Right) (H(2) = 1.15, p = 0.56) or Submit (Bottom) (H(2) = 2.14, p = 0.34) are first used. There was a significant effect on the time when Stroke (Left) is first used (H(2) = 9.28, p = 0.01), with a significant difference between Baseline and Panels. However, this difference can be largely attributed to the number of participants who used the SWHIDGET.

4.4.3 Familiarity. Due to the potential impact of familiarity with SWHIDGETS on their discovery, we asked participants to indicate their previous familiarity with different types of SWHIDGETS on a 7-point Likert scale after the interactive part of the experiment. Statistical analysis showed no significant difference in familiarity between the groups assigned to the different TRANSITION TYPES for all SWHIDGET types (System SWHIDGETS – H(2) = 1.856, p = 0.40; View SWHIDGETS – H(2) = 0.011, p = 0.99; List item SWHIDGETS – H(2) = 0.280, p = 0.87, Individual item SWHIDGETS – H(2) = 4.797, p = 0.09). We also found no significant correlation between familiarity with SWHIDGETS and the usage of the SWHIDGETS in the experiment, nor the time until SWHIDGETS are first used, across all participants.

4.4.4 Transition Perception. When examining the agreement with the different transition statements (see Figure 13), we did not find significant differences between the TRANSITION TYPES (Statement 1 (Experience) – H(2) = 1.17, p = 0.56; Statement 2 (Understanding) – H(2) = 2.55, p = 0.28; Statement 3 (Slowed Down) – H(2) = 5.61, p = 0.06; Statement 4 ( Liked) – H(2) = 0.66, p = 0.72).

Participants who had used the available SWHIDGETS throughout the tasks, were prompted to explain how they knew they could swipe from the screen edge to access additional menus and features. Most participants reported coming across the SWHIDGETS 'accidentally' (9) or 'by chance' (5). Some participants reported they assumed such functionality through familiarity with other interfaces featuring similar swidgets (5) or through intuition (1), while others stated they simply 'guessed' (2).

Notably, only participants who were shown the Panels TRANSITION mentioned the animation at all. P8 noted that *“at first, it was accidentally. Once I realised about this, I noted that it appears at the beginning of the 'game' but very fast”*. Similarly, P14 stated that they knew about the SWHIDGETS *“thanks to the preview at the beginning of the task and also because I accidentally touched a border”* and P20 reported that *“when starting the task, the side menus were apparent and collapsed. This let me know they existed. But I only knew how to access them by error when trying to draw”*. The sole participant who appeared to discover the SWHIDGETS exclusively due to the animation (P32), was hesitant and asked whether *“the colour in the animation, can it be used?”*, stating *“I did not try it myself though I thought about it, but thanks to the animation at the beginning”*. Conversely, another participant in the Panels condition stated they became aware of the SWHIDGETS, because they *“guessed after a few tasks but there was no sign”* indicating that perception of the transition animation varies substantially between individuals.

Despite this variance between participants, qualitative analysis of the responses suggests that the Panels TRANSITION TYPE was the most noticeable, given that it was the only TRANSITION TYPE participants cited as a source of awareness of swidgets. However,
<figure><img src="image_11.png" /><figcaption>Figure 10: Seconds until the first use of a SWHIDGET from the time it becomes available considering only participants who used a given SWHIDGET (a) or considering all participants, using total completion time for participants who failed to use the SWHIDGET during the experiment (b) with the number of datapoints for a given boxplot being displayed below it.</figcaption></figure>

when considering the noticeability ratings, there was no significant effect of TRANSITION TYPES on the reported noticeability ($H(2) = 0.48, p = 0.79$, see Figure 14). A possible explanation could be that participants simply did not consider the sliding panels to be a part of the TRANSITION.

# 5 Study 2 - Impact of Extended Transition Durations

The previous transition duration of 750ms was determined through related work and a preliminary study that suggested transitions at this duration afford noticeability of the animated content (see supplementary material). However, even participants who not only noticed the TRANSITIONS, but listed them as part of why they were aware of the SWHIDGETS, did not infer the availability of the input. This begs the question whether noticed visual depictions actually result in improved discoverability of interactions.

To explore this, we repeated the experiment with an extraordinarily long TRANSITION duration of 5000ms showing a slow-motion animation [45]. While this duration is not conceivable for real world implementation, it eliminates any chance of lacking discoverability simply due to participants not noticing the TRANSITION and allows us to further examine their perception and interpretation. We did not test an extended version of the *Baseline* as there were no signifiers to notice and the extended transition time would merely disrupt participants execution of the tasks.

## 5.1 Participants Study 2

We recruited 22 new participants via word of mouth who had not participated in the previous study (11 *Container Transform 5000ms*, 11 *Panels 5000ms*), aged 18 to 42 (Mean=28.91, SD=6.44) with 13 identifying as men and 9 as women. They were not compensated for their participation. We then analyse their results in relation to the groups reported on in section 4 (*Baseline, Container Transform, Panels*) leading to a total of 55 participants across 5 conditions.

## 5.2 Results Study 2

We use the same metrics as section 4.4 to analyse and compare the impact of the 4 TRANSITION TYPES and the *Baseline*.

5.2.1 **Usage.** We again examined cumulative values of discovery, considering a binary discovered/not discovered per participants across all SWHIDGETS and TASKS 1-5. Again, no significant difference was found ($\chi^2(4) = 3.77, p = 0.44$), with power analysis showing our experiment could detect an effect size of 0.52, corresponding to a moderate to large effect [10]. As in the previous study, no significant effect of the TRANSITION TYPES on SWHIDGET usage across TASKS was found ($\chi^2(36) = 34.68, p = 0.53$, see Figure 11). Additionally, there was no significant difference in the odds of using the swhidgets between the *Baseline* and the TRANSITIONS featuring signifiers (*Container Transform, Panels, Container Transform 5000ms, Panels 5000ms*) (OR = 0.74, 95% CI [0.05, 42.21]).

Notably for the 5000ms transitions, some participants who did notice the *Submit (Bottom) SWHIDGET* in the animation simply considered it superfluous since they only noticed it after having found an alternative way of submitting the TASK, stating things like *"I did not notice that in the first [task], maybe [I noticed it] in the fourth? But by then I had this [pointed at 3-dot menu] and it was easier"* (P214). Nonetheless the majority of participants reported they had not noticed the *Submit (Bottom) SWHIDGET* in the TRANSITION, even when citing it as the source of discovery for the other SWHIDGETS.

5.2.2 **Timing.** For the *Stroke (Left) SWHIDGET*, no significant effect of TRANSITION TYPE conditions (*Baseline, Container Transform, Panels, Container Transform 5000ms, Panels 5000ms*) was found on the time until it was first used. However, significant effects were found for *Colour (Right) (H(4) = 11.97, p = 0.02)* and *Rating (Left/Right) (H(4) = 13.07, p = 0.01)* (see Figure 12). Dunn's test reveals a significant difference (p < 0.05) for the *Colour (Right) SWHIDGET* between *Container Transform (Mean=145s)* and *Panels 5000ms* (Mean=54s). For the *Rating (Left/Right) SWHIDGET* there was
<figure><img src="image_12.png" /><figcaption>Figure 11: Plot showing percentage of participants that used a given SWHIDGET per TASK and TRANSITION TYPE. Note that the results for *Baseline*, *Container Transform* and *Panels* are repeated from subsection 4.4 and are presented in the same colours with decreased opacity to ease understanding.</figcaption></figure>

a significant difference between the *Baseline* (Mean=74s) and *Panels 5000ms* (Mean=28s). In both cases, the *Panels 5000ms* TRANSITION performs significantly better.

Again, we substitute the time for participants who did not use a given swidget through their total completion time. This reveals a significant difference for both the *Stroke (Left)* SWHIDGET ($H(4) = 14.38, p = 0.001$) and the *Colour (Right)* SWHIDGET ($H(4) = 13.84, p = 0.001$). Dunn's test reveals a significant difference for the *Stroke (Left)* SWHIDGET between the *Baseline* (Mean=451s) and the *Panels* TRANSITION at both 750ms (Mean=164s) and 5000ms (Mean=162s). For the *Colour (Right)* SWHIDGET the results reflect the analysis without participants who never discover the SWHIDGET with a significant difference between *Container Transform* (Mean=229s) and *Panels 5000ms* (Mean=54s).

### 5.2.3 Transition Perception.
In contrast to our previous results, when examining the agreement with the different transition statements (see Figure 13) including the 5000ms TRANSITIONS, we find a significant difference between the TRANSITION TYPES for Statement 1 (Experience) – $H(4) = 13.39, p = 0.01$; Statement 2 (Understanding) – $H(4) = 13.68, p = 0.01$ and Statement 3 (Slowed Down) – $H(4) = 18.06, p = 0.001$.

Dunn's test reveals, that for Statement 1 (Experience), there is a significant difference between the *Panels 5000ms* TRANSITION (Mean=6.27) and all other TRANSITION TYPES (Means - *Baseline* =4.09, *Container Transform* =4.73, *Container Transform 5000ms* =4.73, *Panels* =5.00). For Statement 2 (Understanding) there is a significant difference between the original *Baseline* (Mean=4.18) and *Container Transform* (Mean=4.18) and the extended TRANSITIONS *Container Transform 5000ms* (Mean=5.81) and *Panels 5000ms* (Mean=6.27). For Statement 3 (Slowed) there is a significant difference between the *Baseline* (Mean=2.82) and the *Panels* (Mean=1.55) TRANSITION, with *Panels* being perceived as the TRANSITION that slowed down participants the least. Looking at the TRANSITIONS with extended durations, they were both perceived to slow down participants significantly more than their 750ms counterparts (*Container Transform* Mean=1.91 - *Container Transform 5000ms* Mean=4.27; *Panels* Mean=1.55 - *Panels 5000ms* Mean=2.82). In addition there is a significant difference between *Panels* and *Container Transform 5000ms*.

There was no significant difference between TRANSITION TYPES for Statement 4 ( Liked) – $H(4) = 3.66, p = 0.45.$

*Noticeability.* There is a significant difference in the Likert ratings regarding how noticeable the TRANSITIONS were ($H(4) = 20.17, p = 0.001$). There is a significant difference in reported noticeability between the two extended TRANSITIONS *Container Transform 5000ms* (Mean=5.45) and *Panels 5000ms* (Mean=5.09) and all other transitions (*Baseline* Mean=2.82, *Container Transform* Mean=2.55, *Panels* Mean=3.18), highlighting that the 5000ms TRANSITIONS were considered to be significantly more noticeable.

When asking participants how they became aware of the SWHIDGETS, responses for the *Container Transform 5000ms* TRANSITION varied, with some describing the discovery as accidental (P201, P205, P207), random (P219) or based on familiarity with similar interactions (P203, 212). It should be noted that participants may have considered their discovery to be due to familiarity because the animation reminded them of the swidgets. Four participants in this condition made references to the TRANSITIONS, stating “*The way how the task appeared as zoom in made me figure out that more options existed, so I [...] tried and it worked, but it was not so clear or trivial to guess.*” (P209), “*I knew there was something to change colors thanks to the transitions but I couldn’t figure how to use it easily*” (P215) and “*I though it was possible only because the screen started large with the tools on the sides and then zoomed. I guessed there was a way to get the tools I saw previously and the first reflex was to swipe*” (P221). However, these statements also highlight that participants struggled to infer the interaction availability solely through the TRANSITION, with them describing their experience as “*not so clear*” and “*I couldn’t figure how to use it easily*”. This is further supported by participants misinterpreting the availability of SWHIDGETS, stating “*the transition made me think that an interaction was possible when it wasn’t. In the questionnary part, the same transition lead to two different type of interaction and it was confusing*” (P17).

In contrast, 9/11 participants in the *Panels 5000ms* TRANSITION condition made explicit reference to the TRANSITION as the source of their discovery of SWHIDGETS. Nonetheless, two of them also highlighted their confusion, stating “*At the begining, I was so confused, because I saw the animation at the begining but I did not know how to access to that*” (P213) and “*[the SWHIDGETS] appeared at the beginning of the exercise, but I wasn’t sure how to use them at first so I asked*”. Additionally, the least familiar Submit (Bottom) SWHIDGET was cause for confusion with participants stating “*I saw the sliding menu disappear on the side of the screen. But I also thought there was a menu at the bottom but did not find it*” (P204) and “[the TRANSITION] was noticeable but not all of it, because I didn’t see the submit shortcut at the start” (P216).

Across both conditions, multiple participants made note of the slowness of the TRANSITION, making suggestions to progressively decrease duration stating the TRANSITIONS were “*important for the first and second task, not needed after*” (P218) and “*I would say that the transition helped me the first time to discover the features of swiping but once I understood I could do that I would have preferred faster transitions*” (P221).
<figure><img src="image_13.png" /><figcaption>Figure 12: Seconds until the first use of a SWHIDGET from the time it becomes available considering only participants who used a given SWHIDGET (a) or considering all participants, using total completion time for participants who failed to use the SWHIDGET during the experiment (b) with the number of datapoints for a given boxplot being displayed below it.</figcaption></figure>

<figure><img src="image_14.png" /><figcaption>Figure 13: Plot showing participants agreement rating with the statements “The transition between views improved my experience”, “The transition between views improved my understanding of the interface”, “The transition between views slowed me down” and “I liked the transition between views” on a 7-point Likert scale, separated by transition type.</figcaption></figure>

# 6 Discussion

The results of our studies indicate that interaction signifiers em-
bedded in animated transitions do not universally improve the
discoverability of swhidgets. This contrasts the premise of previ-
ous work, that increased visual depiction would increase awareness
of a feature or interaction method [28], as touched on in section 2.1.
While the assumption that differently implemented visual signifiers
would behave similarly across contexts disregards the complexity
of user attention, no previous work on visual signifiers indicates
their limitations as clearly as our findings. Power analysis shows

that our studies would be able to detect a medium to large effect of
added signifiers on the discovery of swhidgets. While it is possible
there is a small to medium effect, the previous success of signi-
fiers and our addition of extremely slow transitions make the lack
of a bigger effect surprising nonetheless. This raises interesting
questions about the noticeability of signifiers, whether increased
noticeability actually translates to increased discoverability, the
perception and potential of transitions as well as the methodology
of studying interaction discoverability.
<figure><img src="image_15.png" /><figcaption>Figure 14: Plot showing the reported noticeability of the transition on a 7-point Likert scale separated by transition type.</figcaption></figure>

## 6.1 Are Temporary Interaction Signifiers in Transitions Noticeable?

In the initial study, no group rated the transition higher than an average of '3 - Somewhat Noticeable', which is not surprising given that the transitions were intentionally integrated to not be the obvious focus of the study. However, participant comments highlight that transitions were noticeable, as even participants who did not use the shhidgets or reported not noticing them were able to describe the transitions (e.g. P5 (Panels) "*the screen splits in the middle to give way for the task space*"). Nonetheless, the follow-up study with 5000 ms transitions highlighted that very slow transitions are considerably more noticeable, with the trade-off being that participants considered them exceedingly slow and thought they were slowing them down.

Regardless of duration, the context of the study may also have changed the perception of transitions. We presented tasks to participants to replicate conventional interaction scenarios and shift the focus away from the transitions. This was confirmed by statements like "I was so focused [...] that I did not realise there were transitions" (P6 - Container Transform) and "I didn't pay attention to it at the time" (P29 - Panels). The participants' notion of what is important in the study may contribute to a focus on the tasks themselves, disregarding anything else and therefore not considering the transitions due to a production bias [5] and inattention and change blindness [12, 32]. While this highlights that the implemented task context might have reduced the noticeability of the signifiers embedded in animated transitions, it reflects real use cases in which users are likely to be focused on either their interaction goals or the content they are engaging with, rather than the interface they are utilising. Nonetheless, this disregard for transitions suggests that they may not be a suitable location for interaction signifiers in general.

However, given the ability of participants to describe the transitions and the increasing need to use the shhidgets to complete the task, it is surprising that the perception of the transitions does not appear to translate into increased discovery of the shidgets or exploration of the interface at a normal transition duration or even the slow-motion 5000 ms *Container Transform* transition.

## 6.2 Why doesn't Noticeability Translate to Improved Discoverability?

While participants noticed the signifiers, they did not improve the discovery of shidgets. However, once shidgets were discovered they were the preferred interaction method over alternatives, confirming previous findings [39] and showing an interest in the use of shidgets. This demonstrates that the lack of use can not be

attributed to a lack of interest and suggests that insufficient discoverability is a main source of low shridget usage.

Potential explanations are user focus and motivation, visualisation not translating to interaction and the preconceived perception of shidgets.

Participant comments suggest that they were focusing on "*changes in the interface*" but "*did not realise there were transitions*", indicating, that animated transitions are not perceived as relevant to the interaction and observations of signifiers embedded in them are discarded without further consideration. Notably, the *Panels 5000ms TRANSITION* was more successful in capturing the participants' attention and supporting the discovery of shhidgets. This may be attributed to both the animation diverging from the established pattern, and therefore garnering attention, and the fact that it incorporates a translation that mirrors the signified interaction, easing its inference and subsequently its discovery. Additionally, discovery of alternative interactions depends on users' motivation which in turn depends on how bothersome existing interactions are [31]. Potentially, extended use of the system would have incentivised participants to seek out the more convenient interaction through shidgets. This would have been further supported by continued exposure to the signifiers, beyond the 6 animated transitions shown during the experiment.

When examining the relationship of noticeability to discoverability, the translation of signifiers into actions seems pertinent. Even participants who noticed the transitions, and listed them as part of why they were aware of the shidgets, did not infer the availability of the input. For instance, P20 states "*when starting the task, the side menus were apparent and collapsed. This let me know they existed. But I only knew how to access them by error when trying to draw*", and P32 was hesitating to try and access the shridget independently, despite seeing the animation and wondering whether "*the colour in the animation can be used*". Similarly, participants in the 5000 ms conditions, who had time to look at the animation, struggled to connect the visual depiction of the shridget to their availability, stating "*The way the task appeared as zoom-in made me figure out that more options existed, so I have tried and it worked, but it was not so clear or trivial to guess*" (P209), "*I was so confused, because I saw the animation at the beginning but I did not know how to access to that*" (P213), "*I knew there was something to change colors thanks to the transitions but I couldn't figure how to use it easily*" (P215) and "*They appeared at the beginning of the exercise, but I wasn't sure how to use them*" (P218). This indicates that noticed signifiers did not result in improved discoverability because participants struggled to infer action from the visualisation. This may be exacerbated since the signifiers show the available shridget but not
the associated interaction. While implied through the directional movement of the animation, it was not clear to participants that they could swipe on screen elements. The *Panels* transition shows the required movement in reverse, which may make it a more successful signifier. Notably, despite showing the movement for the *Submit (Bottom)*, this did not translate to discovery of the shwidget in question, which suggests that discovery of interactions users are not expecting is especially challenging. If an interaction is not established previously and is not part of users' possible input toolkit, they may not interpret it as possible. Additionally, the signifiers are displayed before the interaction is available, and most importantly needed. Although the shwidgets are available immediately after the transition, participants were primarily focused on assessing their task during the initial moments of each task. It is therefore possible that a different moment in the user flow might be better suited for introducing temporary visual signifiers, like depictions of the shwidgets after that assessing phase, that might have garnered more success by showing their availability when needed. This is supported by previous work, noting that users are too engaged in their task to put cognitive effort into finding alternative ways to accomplish it [5], and that signifiers concurrent to the interaction are more successful [28].

Finally, shwidgets may be largely associated with their command, rather than with the component in which they are embedded. Users may be aware that they can, for example, delete a list item by swiping on it and therefore only consider this interaction in this exact context and with this specific aim. This is supported by previous work [39] finding that users suspected the presence of shwidgets in screen layout mirroring those in which they were familiar with shwidgets, making it unlikely for them to discover shwidgets in new contexts. Since the list view in our experiment does not allow users to delete the items, but asks them to agree or disagree with the statements, participants may not associate the shwidget with the desired command and therefore discard the input because they deem it to be improbable.

## 6.3 What do our Results Mean for Temporary Interaction Signifiers and Animated Transitions?

Our results suggest that, for integrated interaction signifiers to be successful, they need to not only be *noticeable* and attract attention, but also to be *comprehensible*.

The fact that participants reported focusing on *"changes in the interface"* but *"did not realise there were transitions"*, suggests that they did not consider the transition to be a part of the interface. While the state of the art suggests that animated transitions are successful in conveying information about the layout of applications and can support users in building more accurate mental models [23, 27], these comments indicate that the participants' mental model of the task and transitions may have led them to view the transitions as superfluous, ignoring them in favour of focusing on the task. This suggests that it may be difficult to adapt previously decorative or purely navigational UI features to include and transfer interaction information as the users' previous experience may prejudice them to pay no attention to the feature.

However, given that animations are largely underutilised and the addition of interaction signifiers in transition does not impede normal usage, their success in conveying shwidgets to a percentage of users makes their optimal integration a worthwhile consideration. While our experiment includes the repeated exposure to the transition signifiers without significantly improving interaction discoverability, the consistent presence of such added signifiers may improve discovery over time. Long-term implementations would allow the users more opportunities to engage with the animation and explore their meaning in their own time. Alternatively, interaction signifiers in animated transitions may benefit from a long initial duration that could decrease as users discover the signified interaction, contrasting with the idea of progressive disclosure [35]. This approach of initially providing an interaction "crutch" through visual signifiers and progressively concealing them as the user discovers the interface also aligns with the preferences expressed by participants in our experiments.

Additionally, our findings suggest that animations differing from current standards are more effective in attracting attention, as their deviation piques users' curiosity and focuses their attention. Given the lack of comprehension of the interaction signifiers, their design could be adapted to be "Explicit & Instructive" [28] by not only temporarily displaying the widget, but including visual elements like arrows or textual instructions including "swipe" or "scroll". This more instructive approach of signifying purely the required interaction rather than the tools accessible through the interaction may be successful in bridging the cognitive dissonance that appears to limit the conversion of noticeability to comprehension and discoverability. In line with this, our results suggest that subtle interaction signifiers, like the ones employed in this study, may only be successful in conveying the availability of familiar interactions, rather than promote the discovery of novel ones, which is highlighted by the participant in our studies largely failing to discover the more unusual *Submit (Bottom) SWHIDGET*.

## 6.4 Methodology for Studying Discoverability

Discoverability in general has been inconsistently and imprecisely defined [29] and subsequently is rarely studied explicitly [16, 28, 46], leading to a lack of consistent and established methodology. The only standard, of course, is to not inform the user of the existence of the interaction meant to be discovered. Subsequently, as mentioned in section 4.1, studying discoverability has an inherent tension between meaningful results and avoiding discovery triggered through the study instructions and setup itself. To make an interaction not essential but available to be discovered, it can (1) not be the only way to achieve something or (2) not be necessary to complete the task.

This is reflected in the work of Fennedy et al. [16], who employ method (1) to examine a "spontaneous discovery", by making the tested feature available but not necessary to complete the task. They then contrast this to an "enforced discovery" measure which they achieve by removing alternative ways to complete the task, therefore making discovery of the tested feature necessary to complete the tasks set within their experiment. We employ these measures at the end of our studies, with the agree/disagree shwidget in task 5 showing the spontaneous discovery rate and in task 6 showing the
enforced discovery rate. The 100% enforced discovery of the rating
shwidget in task 6 elucidates that task essential inputs are likely to
be discovered, however, since most interactions with smartphones
do not follow strict tasks in a laboratory setting, this may not reflect
the likelihood of real life discovery. In addition to this differenti-
ation, we also study the discoverability of shwidgets that are not
necessary to complete a task (2), through the drawing tools made
available in task 1-4. The categories in which these shidgets fall
are summarised in Table 1. To highlight how this categorisation
compares to previous work, we additionally include said work in
our table.

Since we are interested in testing whether temporary interaction
signifiers improve the discoverability of shwidgets, we utilise cases
in which discovery is not forced, but incentivised, by either provid-
ing features beneficial but not necessary for a task (A) or reducing
temporal cost to execute an action (D). Additionally, we measure
forced discovery through case C. Case B, which was not the focus of
our study and examines spontaneous discovery of alternative ways
to access features already available to users, provides an interesting
perspective for future work.

6.5 Limitations

While our study revealed potential constraints to the efficiency of
temporary visual signifiers and raises interesting questions about
the perception of user interface elements, it is limited through its
specific focus and the restrictions dictated by the aim to study dis-
coverability.

The study of discoverability necessitates the focus on something
else (in our case drawing and rating tasks) to avoid biassing users
towards increased interaction discovery. While necessary, this task
focus is likely to reduce discovery through production biases [5].
Nonetheless, we considered this tradeoff worthwhile as it more
closely resembles real-life usage where the interface is not the
users primary concern, and avoids artificially inflating discovery.

Further, we employ a novel task context. While this allows us to
study the impact of visual signifiers in animated transitions by iso-
lating the signified interaction from its usual context, it is possible
that the signifiers would have been effective within it. Our study
shows that interaction signifiers in animated transitions are not
effective to communicate interactions in a novel interface. How-
ever, our results do not determine whether signifiers in animated
transitions might act as a mnemonic for interactions in familiar
contexts.

Although our results contrast with those of previous studies
regarding visual signifiers, it is difficult to draw generalizable con-
clusions since there is very little research specifically focused on the
implementation, perception and effectiveness of visual signifiers.
While temporary visual signifiers have been shown to successfully
signify interactions on static elements like buttons [28], they have
not been explicitly studied for other UI elements, nor have they
been examined with the signifier being temporarily displayed as
part of another interface element or asynchronously to the interac-
tion outside of our study. This limits comparisons and extrapolation
regarding the effect of visual signifiers in general.

Finally, we investigate a very specific type of input. While swid-
gets were carefully selected as both particularly suitable to be in-
corporated into transitions due to their positioning and in need of
improved discoverability due to their inherently hidden nature, we
can't be certain that visual signifiers in animated transitions are
not successful in conveying other inputs more consistently.

6.6 Future Work

Given that our results suggest temporary interaction signifiers
implemented into commercially viable animated transitions do
not work as interaction signifiers, future work should additionally
explore the perception of users as well as the characteristics and
limits of temporary visualisations that may aid discoverability.

*Mental Models*. Since our results suggest that some participants do not consider transitions to be part of the interface, future work should investigate how participants conceptualise animated transitions and whether this mental model may lead them to exclude transitions from any further considerations if they are perceived to be purely decorative. This additionally raises the question of whether decorative features in interfaces are generally assessed as irrelevant and subsequently ignored and how much they may need to be altered to elude this categorisation.

Additionally, future work should examine how animated transi-
tions impact users’ mental model of the UI, since even conscious
perception of the shwidgets in the transition did not translate to
interaction and discovery of them. This is especially interesting
since this contrasts previous work, which suggests that animated
transitions successfully improved the mental model of the app
structure [23]. There appears to be a limitation to when animated
transitions support accurate mental models that may depend on
context, which is worth exploring. As they are widely employed
to support navigational understanding, can they only be used to
support top level structural mental models?

*Noticeability and Discoverability.* While noticeability has been widely differentiated from comprehension [46, 48], it is interesting that it also appears to fail to create awareness or arouse curiosity. Although participants noticed the shwidget signifiers in the transitions, this did not translate to awareness of the shwidget. While this may be attributed to a disconnect between the transition and the widget, future work should investigate why noticeability does not appear to lead to awareness, arouse curiosity or even nudge participants towards exploration.

*Temporary Visualisation to Improve Discoverability.* Given that animated transitions did no improve discoverability, the potential of alternative transitions as well as general temporary visual signifiers should be examined.

First, transitions with extremely long durations could be ex-
plored further. This may prove interesting in combination with
considerations of the mental model, as extremely slow transitions
may lead to a change in the perception of transitions and morph
into something akin to a loading screen, which are more established
to include interaction signifiers. However, it should be noted that 5
seconds did not appear to be long enough for established transition
styles to be perceived differently. If further duration extensions
prove to be beneficial they could be implemented the first time
<table><caption>Table 1: Classification of task and related work discoverability methodology.</caption><thead><tr><th></th><th>No alternative way of completing task</th><th>Alternative way of completing task</th></tr></thead><tbody><tr><td>Not necessary to complete task</td><td><strong>A Discovery is not forced</strong><br>Task 1,2,3,4 Swhidget Colour (Right)<br>Task 1,2,3,4 Swhidget Stroke (Left)<br>Walter et al. [46] StrikeAPose</td><td><strong>B Discovery is not forced nor encouraged</strong><br>Goguey et al. [18]</td></tr><tr><td>Necessary to complete task</td><td><strong>C Discovery is forced</strong><br>Task 6 Swhidget Rating (Left/Right)<br>Fennedy et al. [16] Enforced Discovery<br>Mackamul et al. [28] In-Place Touch Inputs</td><td><strong>D Discovery is not forced</strong><br>Task 5 Swhidget Rating (Left/Right)<br>Task 1,2,3,4,5,6 Swhidget Submit (Bottom)<br>Fennedy et al. [16] Spontaneous Discovery</td></tr></tbody></table>

an application is opened as an alternative or complementary to onboarding [22].

Alternatively, it could be explored whether alternative design of visual signifiers in animated transitions could improve their effectiveness. Highlighting the shwidgets in the transitions more clearly by displaying only them and introducing the original app content at the end, or through added animation like blinking, drawing the attention of users to that specific part of the screen, may improve discoverability. Additionally, transitions could be augmented with explicit signifiers that feature stronger visual elements like arrows or text with concrete interaction instructions.

Finally, if transitions fall into a category of UI components that are inherently disconnected from interaction in people's minds, other temporary visualisations may prove to be more beneficial. Since previous work is inconclusive about the importance of temporal placement for interaction signifiers concerning single finger, in-place inputs [2, 28], future work could investigate animation concurrent to the need for an action embedded in a shwidget and whether this improves discoverability. Additionally, animation visualising the existence of the shwidget if the action (or a related action) is performed in an alternative way could signify the availability of swipe interactions.

## 7 Conclusion

While temporary visual interaction signifiers embedded in animated transitions may increase noticeability, this does not improve the discoverability of shwidget interactions with our sample. This raises questions of how transitions are conceptualised in users' minds, whether decorative UI elements are automatically disregarded, if interaction signifiers need to be concurrent to the interaction as well as whether increasing noticeability fosters discoverability in general. Given the previously supported hypothesis that increased visualisation improves discoverability and the success of using animated transitions to convey information, this provides a compelling indication of how interaction availability may be conceptualised differently than assumed and how inputs are discovered while offering paths for future work.

## 8 Acknowledgements

This work was supported by the Agence Nationale de la Recherche Discovery (ANR-19-CE33-0006) and SecondSkin (ANR-21-CE33-0018) projects, the Natural Sciences and Engineering Research Council of Canada (RGPIN-2018-05072), Mitacs Globalink and the

Université de Lille's MOBilité - LILle - EXcellence (MOB-LIL-EX) program.

## References

[1] Caroline Appert, Olivier Chapuis, and Emmanuel Pietriga. 2012. Dwell-and-Spring: Undo for Direct Manipulation. In *Proceedings of the SIGCHI Conference on Human Factors in Computing Systems* (Austin, Texas, USA) (CHI '12). Association for Computing Machinery, New York, NY, USA, 1957–1966. https://doi.org/10.1145/2207676.2208339

[2] Liv Arleth, Emilie Lind Damkjær, and Hendrik Knoche. 2020. “But Wait, There’s More!” a Deeper Look into Temporally Placing Touch Gesture Signifiers. In *Interactivity, Game Creation, Design, Learning, and Innovation: 8th EAI International Conference, ArtsIT 2019, and 4th EAI International Conference, DLI 2019, Aalborg, Denmark, November 6–8, 2019, Proceedings 8*. Springer, 290–308. https://doi.org/10.1007/978-3-030-53294-9_20

[3] Ronald Baecker and Ian Small. 1990. Animation at the interface. *The art of human-computer interface design* (1990), 251–267.

[4] Stuart K Card. 2018. *The psychology of human-computer interaction*. Crc Press.

[5] John M. Carroll and Mary Beth Rosson. 1987. *Paradox of the active user*. MIT Press, Cambridge, MA, USA, 80–111.

[6] Xiang 'Anthony' Chen, Julia Schwarz, Chris Harrison, Jennifer Mankoff, and Scott E. Hudson. 2014. Air+touch: interweaving touch & in-air gestures. In *Proceedings of the 27th Annual ACM Symposium on User Interface Software and Technology* (Honolulu, Hawaii, USA) (UIST '14). Association for Computing Machinery, New York, NY, USA, 519–525. https://doi.org/10.1145/2642918.2647392

[7] Fanny Chevalier, Pierre Dragicevic, and Steven Franconeri. 2014. The not-so-staggering effect of staggered animated transitions on visual tracking. *IEEE transactions on visualization and computer graphics* 20, 12 (2014), 2241–2250.

[8] Fanny Chevalier, Nathalie Henry Riche, Catherine Plaisant, Amira Chalbi, and Christophe Hurter. 2016. Animations 25 years later: New roles and opportunities. In *Proceedings of the international working conference on advanced visual interfaces*. 280–287.

[9] Josh Clark. 2015. *Designing for touch*. A Book Apart New York.

[10] Jacob Cohen. 1992. Statistical power analysis. *Current directions in psychological science* 1, 3 (1992), 98–101.

[11] Javier Cuello and José Vittone. 2013. *Designing mobile apps*. José Vittone.

[12] Thomas Davies and Ashweeri Beeharee. 2012. The case of the missed icon: change blindness on mobile devices. In *Proceedings of the SIGCHI Conference on Human Factors in Computing Systems* (Austin, Texas, USA) (CHI '12). Association for Computing Machinery, New York, NY, USA, 1451–1460. https://doi.org/10.1145/2207676.2208606

[13] Apple Developer Design. 2023. Apple Developer - Design - Human Interface Guidelines - Going Full Screen. https://developer.apple.com/design/human-interface-guidelines/going-full-screen

[14] Apple Developer Design. 2023. Apple Developer - Design - Human Interface Guidelines - Launching. https://developer.apple.com/design/human-interface-guidelines/launching

[15] Pierre Dragicevic, Anastasia Bezerianos, Waqas Javed, Niklas Elmqvist, and Jean-Daniel Fekete. 2011. Temporal Distortion for Animated Transitions. In *Proceedings of the SIGCHI Conference on Human Factors in Computing Systems* (Vancouver, BC, Canada) (CHI '11). Association for Computing Machinery, New York, NY, USA, 2009–2018. https://doi.org/10.1145/1978942.1979233

[16] Katherine Fennedy, Angad Srivastava, Sylvain Malacria, and Simon T. Perrault. 2022. Towards a Unified and Efficient Command Selection Mechanism for Touch-Based Devices Using Soft Keyboard Hotkeys. *ACM Trans. Comput.-Hum. Interact.* 29, 1, Article 4 (jan 2022), 39 pages. https://doi.org/10.1145/3476510

[17] Emmanuelil Giannisakis, Gilles Bailly, Sylvain Malacria, and Fanny Chevalier. 2017. IconHK: Using toolbar button icons to communicate keyboard shortcuts. In *Proceedings of the 2017 CHI Conference on Human Factors in Computing Systems*. 4715–4726.
[18] Alix Goguey, Sylvain Malacria, and Carl Gutwin. 2018. Improving Discoverability and Expert Performance in Force-Sensitive Text Selection for Touch Devices with Mode Gauges. In Proceedings of the 2018 CHI Conference on Human Factors in Computing Systems. Association for Computing Machinery, New York, NY, USA, 1-12. https://doi.org/10.1145/3173574.3174051

[19] Carl Gutwin, Andy Cockburn, and Benjamin Lafreniere. 2015. Testing the re-hearsal hypothesis with two FastTap interfaces. In Proceedings of the 41st Graphics Interface Conference (Halifax, Nova Scotia, Canada) (GI '15). Canadian Information Processing Society, CAN, 223-231.

[20] Carl Gutwin, Andy Cockburn, Joey Scarr, Sylvain Malacria, and Scott C. Olson. 2014. Faster command selection on tablets with FastTap. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems (Toronto, Ontario, Canada) (CHI '14). Association for Computing Machinery, New York, NY, USA, 2617-2626. https://doi.org/10.1145/2556288.2557136

[21] Jussi Huhtala, Ari-Heikki Sarjanoja, Jani Mäntyjärvi, Minna Isomursu, and Jonna Häkkilä. 2010. Animated UI Transitions and Perception of Time: A User Study on Animated Effects on a Mobile Screen. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems (Atlanta, Georgia, USA) (CHI '10). Association for Computing Machinery, New York, NY, USA, 1339-1342. https://doi.org/10.1145/1753326.1753527

[22] Alita Joyce. 2020. Mobile-App Onboarding: An Analysis of Components and Techniques. Retrieved January 27th, 2022 from https://www.nngroup.com/articles/mobile-app-onboarding/.

[23] Jonas F Kraft and Jörn Hurtienne. 2017. Transition animations support orientation in mobile interfaces without increased user effort. In Proceedings of the 19th International Conference on Human-Computer Interaction with Mobile Devices and Services. 1-6.

[24] Vincent Lambert, Adrien Chaffangeon Caillet, Alix Goguey, Sylvain Malacria, and Laurence Nigay. 2023. Studying the Visual Representation of Microgestures. In ACM International Conference on Mobile Human-Computer Interaction (MobileHCI 2023).

[25] Moon-Hwan Lee, Da-Hoon Kim, Hyun-Jeong Kim, and Tek-Jin Nam. 2012. Understanding impacts of hidden interfaces on mobile phone user experience. In Proceedings of the 7th Nordic Conference on Human-Computer Interaction: Making Sense Through Design (Copenhagen, Denmark) (NordiCHI '12). Association for Computing Machinery, New York, NY, USA, 45-48. https://doi.org/10.1145/2399016.2399024

[26] Material Design M3. 2023. Easing and duration - Applying easing and duration. https://m3 material.io /styles /motion /easing-and-duration /applying-easing-and-duration

[27] Material Design M3. 2023. Transitions - Transitions help guide users as they navigate an app - Transition Patterns. https://m3 material.io /styles /motion/ transitions /transition-patterns

[28] Eva Mackamul, Géry Casiez, and Sylvain Malacria. 2023. Exploring Visual Signifier Characteristics to Improve the Perception of Affordances of In-Place Touch Inputs. In ACM International Conference on Mobile Human-Computer Interaction (MobileHCI 2023).

[29] Eva Mackamul, Géry Casiez, and Sylvain Malacria. 2024. Clarifying and differentiating discoverability. Human-Computer Interaction 0, 0 (2024), 1-26. https://doi.org/10.1080/07370024.2024.2364606

[30] Saipunidzam Mahamad, Fasihah Mohammad Shuhaili, Suziah Sulaiman, Dayang Rohaya Awang Rambli, and Abdullateef Oluwagbemiga Balogun. 2022. Visual Signifier for Large Multi-Touch Display to Support Interaction in a Virtual Museum Interface. Applied Sciences 12, 21 (2022), 11191.

[31] Sylvain Malacria, Joey Scarr, Andy Cockburn, Carl Gutwin, and Tovi Grossman. 2013. Skillometers: reflective widgets that motivate and help users to improve performance. In Proceedings of the 26th Annual ACM Symposium on User Interface Software and Technology (St. Andrews, Scotland, United Kingdom) (UIST '13). Association for Computing Machinery, New York, NY, USA, 321-330. https://doi.org/10.1145/2501988.2501996

[32] Gabriela Mancero, William Wong, and Paola Amaldi. 2007. Looking but not seeing: implications for HCI. In Proceedings of the 14th European conference on Cognitive ergonomics: invent! explore! 167-174.

[33] Benedikt Merz, Alexandre N. Tuch, and Klaus Opwis. 2016. Perceived User Experience of Animated Transitions in Mobile User Interfaces. In Proceedings of the 2016 CHI Conference Extended Abstracts on Human Factors in Computing Systems (San Jose, California, USA) (CHI EA '16). Association for Computing Machinery, New York, NY, USA, 3152-3158. https://doi.org/10.1145/2851581.2892489

[34] Jakob Nielsen. 1994. Usability engineering. Morgan Kaufmann.

[35] Jakob Nielsen. 2006. Progressive Disclosure. Retrieved October 23rd, 2023 from https://www.nngroup.com/articles/progressive-disclosure/.

[36] Donald A. Norman. 2013. The design of everyday things: Revised and expanded edition. Basic books.

[37] Donald A. Norman. 2018. Affordances and design. retrieved January 27th, 2022 from https://jnd.org/affordances_and design/.

[38] Nicole Ke Chen Pong. 2020. Interacting with signifier-less designs—the case of swlidgets. Ph. D. Dissertation. Université de Lille.

[39] Nicole Ke Chen Pong and Sylvain Malacria. 2019. Awareness, Usage and Discovery of Swipe-Revealed Hidden Widgets in IOS. In Proceedings of the 2019 ACM International Conference on Interactive Surfaces and Spaces (Daejeon, Republic of Korea) (ISS '19). Association for Computing Machinery, New York, NY, USA, 193-204. https://doi.org/10.1145/3343055.3359713

[40] Renate Rutiku, Jaan Aru, and Talis Bachmann. 2016. General markers of conscious visual perception and their timing. Frontiers in human neuroscience 10 (2016), 23.

[41] Katherine Schramm, Carl Gutwin, and Andy Cockburn. 2016. Supporting Transitions to Expertise in Hidden Toolbars. In Proceedings of the 2016 CHI Conference on Human Factors in Computing Systems (San Jose, California, USA) (CHI '16). Association for Computing Machinery, New York, NY, USA, 4687-4698. https://doi.org/10.1145/2858036.2858412

[42] Mindy Seto, Stacey Scott, and Mark Hancock. 2012. Investigating Menu Discoverability on a Digital Tabletop in a Public Setting. In Proceedings of the 2012 ACM International Conference on Interactive Tabletops and Surfaces (Cambridge, Massachusetts, USA) (ITS '12). Association for Computing Machinery, New York, NY, USA, 71-80. https://doi.org/10.1145/2396636.2396647

[43] John Thompson, Zhicheng Liu, Wilmot Li, and John Stasko. 2020. Understanding the design space and authoring paradigms for animated data graphics. In Computer Graphics Forum, Vol. 39. Wiley Online Library, 207-218.

[44] Marcus Trapp and René Yasmin. 2013. Addressing animated transitions already in mobile app storyboards. In Design, User Experience, and Usability. Web, Mobile, and Product Design: Second International Conference, DUXU 2013, Held as Part of HCI International 2013, Las Vegas, NV, USA, July 21-26, 2013, Proceedings, Part IV 2. Springer, 723-732.

[45] Jo Vermeulen, Kris Luyten, Karin Coninx, and Nicolai Marquardt. 2014. The Design of Slow-Motion Feedback. In Proceedings of the 2014 Conference on Designing Interactive Systems (Vancouver, BC, Canada) (DIS '14). Association for Computing Machinery, New York, NY, USA, 267-270. https://doi.org/10.1145/2598510.2598604

[46] Robert Walter, Gilles Bailly, and Jörg Müller. 2013. StrikeAPose: Revealing Mid-Air Gestures on Public Displays. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems (Paris, France) (CHI '13). Association for Computing Machinery, New York, NY, USA, 841-850. https://doi.org/10.1145/2470654.2470774

[47] Yen-Ting Yeh, Quentin Roy, Antony Albert Raj Irudayaraj, and Daniel Vogel. 2020. Expanding Side Touch Input on Mobile Phones: Finger Reachability and Two-Dimensional Taps and Flicks using the Index and Thumb. Proc. ACM Hum-Comput. Interact. 4, ISS, Article 206 (Nov. 2020), 20 pages. https://doi.org/10.1145/3427334

[48] Stephen L Young. 1991. Increasing the noticeability of warnings: Effects of pictorial, color, signal icon and border. In Proceedings of the Human Factors Society Annual Meeting, Vol. 35. Sage Publications Sage CA: Los Angeles, CA, 580-584.