UX as Science
Jinsoo Kim Ph.D.

My Background• Education• Electrical Engineering (B.A.)• Education (B.A. and M.A.)• Cognitive Science (Ph.D.)• Specialized in HCI (Human-Computer Interaction)• Business• Fmr Yahoo! Korea• Head of UED (User Experience & Design)• Front Page Manager• Product Development Process Champion• Head of Product Council• CEO• Fmr Chairman of Kipfa (Korea Internet ProfessionalsAssn.)

User eXperienceExperience in Economy

memorable events --> experienceUX belongs to Usable?

Alan Dix, the author of Human-Computer Interaction

UX vs. UI
Neilson Norman GroupEven if the UI for finding a film is perfect, the UX
will be poor for a user who wants information
about a small independent release if the underlying
database only contains movies from the majorstudios.
(https://www.nngroup.com/articles/definition-user-experience/)

UI relates to finding but UX to information

UX by ISO 9241-210• "a person's perceptions and responses that
result from the use or anticipated use of a
product, system or service".
• Three factors that influence UX• User’s state and previous experience• System properties and the context of use
ContextSystemUserContext
Yahoo! Japan

User

Interaction vs. Interface

presentationO

outputCH

computerperformanceobservation

GOAL

humanI

articulation

input
interface

Reference: Human-Computer Interaction by Alan Dix, et alWired InternetO

outputS

serverCHhumanclient

I

input

ContextWireless Internet

O

outputS

server

M

H

human

mobileI

input

Context

UI, User Interaction & UXContext

OS

serverM

mobileH

I

human

UI

UX

ContentInteraction Design
Visual Design
FE/BE coding

UsefulUsableDesirable
ReliableHumanPersonal(Access, Depth)

Satisfaction
Segmentation(Demographic, Behavior, Goal)

Common characteristics of Human(Information processing mechanism)

CostHuman Sights• Eye movement• Saccadic movement• Fixation: longer than 300ms• Visual Angle• Horizontal Field of View: 5 degrees• Vertical Field of View: 10 degrees

Eye Tracking

https://youtu.be/lo_a2cfBUGc

Eye Tracking

N=432%

5%

8.3%
30%

11.5%

12%

13.4%

8%

Search BUCKET Test
Test-1

Test-2

Test-3

Results
V_Search
1.4
1.2
1
Test1
Tes2
Test3

0.8
0.6
0.4
0.2
020040607

20040608

20040609

20040610

20040611

20040612

20040613

More Choice is Better?
• “Paradox of Choice” by Barry Schwartz• “fact that some choice is good doesn't necessarily mean that
more choice is better. ... There is a cost to having an overloadof choice.”Bigger Search Box à More chance to use?

Visual Weight and Context

Mistreatment of Visual WeightIntuition vs. Data
• Real Time Tracking• Faster tracking for immediate action• Contextual coupling between an article and its performance

News - Result• News PV in May spiked over 905M PV, reached +78.5% against Apr 07905M

851M
826MM800750

758M
748M

+78.5%

Source: DYC

717M
692M

673M

700

661M

650

610M

600

-2.5%

575M

550

540M

513M
500

504M

576M
578M

549M

546M
507M
497M

501M

486M
475M

464M

450
400

650M

Apr’06 May Jun Jul Aug Sep Oct Nov Dec Jan Feb MarYAHOO! CONFIDENTIAL

507M

New Management

Apr’07 May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May

Designing Touch Interfaces• Designing Visual Targets• the link text, icon, or other graphic element that affords aninteraction• Designing Touch Targets• An area on a screen that a user can touch to perform an action• Preventing interference errors• The circular error of probability for one target includes anothertarget as well

Visual Targets: Big Enough and Clear Enough• The link text, icon, or other graphic element that affords
an interaction• They attract the user’s eye• The user understands that they are actionable elements• They are readable, and the user can understand what action
they will perform• The user is confident that he will easily tap themAngles of Vision

Devices that a user is viewing further away requires larger fonts

Minimum and Maximum Font Size
• Minimum font size

• Must meet three criteria: readable, legible, and tappable• Text: 6 point (pt) or 2.1 millimeter (mm)• Icons: 8 point (pt) or 2.8 millimeter (mm)• Maximum font size

• Our area of attention is much smaller than our field of vision• The cone representing our foveal vision: 5 degrees across= a circle that is approximately half the size of your fist at arm’slength• If tappable items are bigger than that, users cannot perceive
them as actionable items

Touch Target• An Area on a screen that a user can touch to perform anaction• Touchscreens sense only the centroid,or geometric center of the contactpatch• The absolute minimum for a reliable
Touch target:• Relatively still: 6 mm
• Moving or distracted: 8 mm

Preventing Interference Errors• Interference• The condition that happens when two or more touch targets are
in close physical proximity• The circular error of probability for one target includes anothertarget as well

• To avoid interference errors• At least 8 millimeters apart on center• 10 millimeter spacing being strongly preferable• To avoid disaster of interference• Never place buttons with catastrophic consequences

Thank you!