QLeaves: Tangible Message Containers for the Vitality
Enhancement of Public Places
MEGHAN DEUTSCHER, † MASAYUKI IHARA †† and MINORU KOBAYASHI ††1. Introduction
QLeaves is a tangible1) digital information container2) system
intended for use in public and shared spaces. With a mobilephone, one can add text and photos to a physical leaf shaped
card called a “QLeaf”. Using real QLeaves to distribute andshare virtual messages in a place creates an information spacethat reflects the people and activities of the place.
Systems for blogging and content distribution in publicplaces, as opposed to from one’s home or office computer, are3)-5)-5). The requirements of these
becoming more prevalent3)
systems are unique from an interaction perspective – having toshare the user’s attention with other activities in place and do
so with more restrictive devices (i.e. a mobile phone), and froma social perspective – weaving system use into the fabric of aplace’s established social behaviors. We wish to study theQLeaves system in a real world setting in order to better
understand these requirements. Focus points for a future studyare derived from discussions during an initial presentation ofQLeaves at a research forum.

simplicity: supporting the largest number of users using
simple, familiar, and widely available interaction methods (amobile phone’s QRcode reading, email, and web browsing
functions).
anonymity: alleviating use hesitation due to shyness orconcerns of privacy.
The QLeaf Object
The QLeaf is a plastic leaf shaped card, around the size of abusiness card, imprinted with a “write” QRcode and a “read”
QRcode (see Fig. 1). The “write” QRcode contains an email
address to which a message to add to the QLeaf may be sent.
The “read” QRcode contains a URL. A QLeaf’s message may
be viewed by accessing this URL in a mobile phone’s web
browser. The email address and URL both contain an ID that is
unique for each QLeaf.

2. Life in a Building
Modern buildings can be sterile, impersonal places. They areclean, organized, and maintained thus sometimes lacking
indicators of culture and history beyond what is fabricated forpresentation purposes. It is desirable to have means for people
in a building to leave personally created content in order todevelop an information space that better represents the culture
and history of the place or “life” in that building.
QLeaves is a public message distribution system throughwhich this information space can be created. The use of a leaf
as an object to which messages can be added and then readfrom is inspired by the ubiquity of fake plants in buildings.
They bring about the vision of leaves strewn over the ground of
a place, an acceptable mess for one to explore and findmessages relevant to that place.

3. QLeaves System
The development of the first QLeaves prototype which is
described in details below was driven by the following:tangibility: using physical objects as containers for digital
messages to add the objects’ affordances and perceived value
to the messages.
message ephemerality: limiting the time a message can becontained in a physical object to induce change in a place’s
information space.
†

Human Communication Technologies Laboratory, University of British
Columbia, Vancouver, Canada††
NTT Cyber Solutions Laboratories, NTT Corporation

Fig 1: An example of a QLeaf

A QLeaf may contain only one message at a time and thismessage will expire after some predetermined period of time(for the first presentation of QLeaves, this time was set to 2hours). After a message expires, the QLeaf becomes empty
again and a new message can be added.
QLeaves Visualization
QLeaves are freely moving objects so their use cannot betied to a place specifically. The connection between QLeaves
usage and a place is made indirectly through the use of avisualization displayed in the place where the QLeaves aredistributed.
The visualization (see Fig. 2) depicts real-time states of all
QLeaves associated with a place. Each QLeaf is represented bya graphical leaf floating slowly in the display. When a message
is added to a QLeaf, its representation becomes green in color.
As the message ages, the color fades through stages of red,orange, yellow, and brown. Finally when the message expires,the displayed leaf loses all color - it is empty. A person may
select a leaf on the display to view its current message, orbrowse archived messages.

Fig. 2QLeaves Visualization

A QLeaves Scenario
There are QLeaves scattered on the shelves of a bookcase
next to the café’s most comfortable chairs. Ben sits down withhis coffee and before opening his book he takes a QLeaf andcaptures the “read” QRcode with his mobile. In a few clicks heis looking at a message written by a former patron of the café.
It includes a quote from a book, the name of a song, and animage of the author’s shoes. Reading two more QLeaves
results in similar messages. This is a routine that some of thecafé customers have. They do it to share their current book andmusic interests with others. It also acts like a personal diary,
but kept in a place they associate with reading good books andenjoying music.
Ben leans over, takes a picture of his feet with his mobile’s
camera and attaches it to a message that includes an enjoyablepassage from last night’s reading. He takes a QLeaf from his
pocket, captures the “write” QRcode, emails his message to thereceived address, and tucks the QLeaf between two books on
the bookshelf. A few moments later he notices two younger
girls looking at the QLeaves display. They select the only green
leaf on the screen and read the message he just added. One girlglances around the room, looking at people’s feet and thencontinues to talk with her friend. Ben chuckles and goes backto reading his book with a smile on his face.

4. Experiences
We presented the above described prototype at SFC ORF
20066), a public research forum held on November 22nd and23rd of 2006. During this event the QLeaves system wasintroduced to between 150 and 200 people. Our presentation
goal was to engage people in discussion of their thoughts on
using a system like QLeaves in order to identify important
points that we could use when framing a future study. The mostprevalent issues discussed were:user privacy and profiling: There was a mixed reaction to theanonymity of QLeaves use. Opinion was highly based on whata person’s motivations would be for using the system. For
example, if a message was written with a target reader in mind,
some indicator of the message’s author would be desirable.
feedback and knowledge of activity: The QLeaf object bears
no information as to whether or not it contains a message. From
one perspective this is a system fault but from another, it keeps
the objects and the space they are used in simple. Without
wanting to “pollute” spaces and objects with indicators of
information space activity, when and how should feedback begiven?
message management: An important aspect of the QLeaves
system is the “management” of messages. We explained how
they are basically managed (a QLeaf can contain one at a timeand it will expire after a predetermined amount of time) andthen discussed variations on this scheme. For example,QLeaves could come in pairs so that a message added to one
could be read from another and vice versa. This discussion
stimulated many other suggestions for forms of message
management (varying time limits on objects, message
categories, visual format, access management, etc.). How dothese possible schemes relate to the context of QLeaves use,
the intentions behind leaving messages, and the motivations toread messages?
public versus personal use: Finally, when asked “how would
you use QLeaves?”, responses with both public use scenarios(leaving messages for strangers) and personal scenarios(sharing QLeaves in a closed group) were given. This produced
thoughts on which elements of this kind of system support
public use and which elements support private use.

5. Future Study
We will implement QLeaves in a real world place to analyze
usage patterns and message content, as well as conduct a morein depth diary study with a smaller group of participants who
regularly frequent the place. Data collection and analysis will
be motivated by the above four issues. Our final goals are notto evaluate the use of the QLeaves system specifically, but togain insight into systems for blogging and message distribution
in public places in general.

References
1) Ishii, H., et al: Tangible bits: towards seamless interfaces
between people, bits and atoms, Proc. of CHI’97, Atlanta,
GA, 234-241 (1997).
2) Ljungstrand, P., et al: Webstickers: Using Physical Tokens toAccess, Manage and Share Bookmarks to the Web, Proc. ofDARE 2000, Elsinore, Denmark, 23-31 (2000).
3) Persson, P., et al: GeoNotes: A Location-based Information
System for Public Spaces, Designing Information Spaces:
The Social Navigation Approach, Höök, K., Benyon, D., andMunro, A. (Ed.), 151-173, Springer (2002).
4) PlaceSite: http://placesite.com/
5) Jacobs, M., et al: Tejp: Ubiquitous Computing as Expressive
Means of Personalising Public Space, Extended Abstracts ofUbicomp 2003, Seattle, WA (2003).
6) SFC ORF 2006: http://orf.sfc.keio.ac.jp/