Human Computer InteractionCSC 4730-100

User System InterfaceCSC 8570-001

Class Meeting 4September 18, 2012

Topics of the Day

• From last time– Where is Gregor?– Track pad interactions

• Research project issues– Bibliography– IRB form– Theory and models

• Good and bad interfaces• Lee & Zhai. Extracting design principles• Cataloging design principles

Where is Gregor?

One thousandth of a minute= 6 x one hundredth of a second

Diameter of earth = 7926 miles, approximatelyClaim: Assuming the earth is a perfect sphere, the

arc of a circle with central angle of 1/100 second is 1.0+ feet long. (latitude)

Claim: At 40 degrees north, the arc of longitudinal circle with central angle of 1/100 second is 0.77+ feet long.

Track Pad Interactions

Cleaning up action descriptions• Tap to click• Secondary click• Look up• Three finger drag• Scroll direction: natural• Zoom in or out• Smart zoom• Rotate• Swipe between pages

Track Pad Interactions (2)• Swipe between full-screen apps• Mission control• App exposé• Launchpad• Show desktop• Pinch to home screen• Swipe up to multitasking• Swipe left or right between apps• Reveal multitasking bar• Between apps

Track Pad Interactions (3)

Cleaning up gesture descriptions• Tap with one finger• Click or tap with two fingers• Click bottom left• Click bottom right• Double-tap with three fingers• Move with three fingers• Content tracks finger movement• Pinch with two fingers

Track Pad Interactions (4)

• Double-tap with two fingers• Rotate with two fingers• Scroll left with two fingers• Scroll right with two fingers• Swipe with three fingers• Swipe with two or three fingers• Swipe left with three fingers• Swipe right with three fingers

Track Pad Interactions (6)

• Swipe left with four fingers• Swipe right with four fingers• Swipe up with three fingers• Swipe up with four fingers• Swipe down with three fingers• Swipe down with four fingers• Pinch with thumb and three fingers• Spread with thumb and three fingers

Track Pad Interactions (7)

• Pinch with four or five fingers• Swipe up with four or five fingers• Swipe left with four or five fingers• Swipe right with four or five fingers

Hand In

• Everyone: GOMS model of table creation• Each research team:– Hypotheses, independent and dependent

variables– First draft of IRB form– Printout from EndNote of research bibliography

Research Project

• Hypotheses (tonight)• Independent variables (tonight)• Dependent variables (tonight)• Bibliography– First entries (tonight)– Continuous process

• Background • Formal setting (let’s talk)

Research Project (2)

For next week, from each team:

• Short presentation– One spokesperson– Five minutes– Hypothesis, variables, initial experimental design– A few slides to guide the listeners

Paper Reading Teams

1. Kristin & Jim B2. John & Andrew D3. Anthony & Kevin4. Chris & Shishir5. Mike & Andrew L6. Donald & Jim N7. Tyler & Ken

Research Project Example

Lee & Zhai, The Performance of Touch Screen Soft Buttons• Team 1: Introduction– What are potential research questions?

• Team 2: Related Work– What is known about interacting with soft buttons?

• Team 3: Basic Issues– What dimensions (?) of touch screens are important?

Example (2)

• Team 4: Methodology– What did the subjects do for Experiment 1? Why this

design?• Team 5: Hard button results, Experiment 1– How are the data summarized and analyzed?

• Team 6: Soft button results, Experiment 1– How are the data summarized and analyzed?

• Team 7: Summary & Conclusions, Experiment 1– What device is best?

Lessons from Lee & Zhai

• Subjects: 13 total – 9 men, 4 women• Overall design: practice, test,

questionnaire/interview• Experiment structure:– Block– Trial

Experimental Design

• Within subjects– vs. Across subjects

• Randomized order of conditions– Generating random numbers

• Balanced Latin square design– Think Sudoku

Experiment 1

• Conditions (10): button type + feedback type• Entry set (5): 1450 X 9276 = ; 8327 – 7231 = ;

etc.• Order of entry set randomized• Block (3): Instances of ordered entry set– How many entry set arrangements are possible?

• One subject generates 3 x 5 x 10 sets of data– Time, # of corrections

Hard ButtonsBlock 1 - A Block 1 - N Block 2 Block 3

Subj 1 5 trials 5 trials

Subj 2

Subj 3

Subj 4

Subj 5

Subj 6

Subj 7

Subj 8

Subj 9

Subj 10

Subj 11

Subj 12

Subj 13

Inferring Design Principles

• Augment soft buttons with synthetic feedback• Make soft buttons at least 10 mm wide• Provide automatic error correction for text

entry using small buttons

Interface Survey

• Good interfaces of the week• Bad interfaces of the week

Good Interfaces

• Who says?• On what basis?• Why were your choices (of helpful interfaces)

good?• What were the design principles that

promoted “goodness”?

Bad Interfaces

• Same questions as for “good”– Who says?– On what basis?

• What design principles were violated?

Good and Bad

• Generative User Engineering Principles (GUEPs)

• Cognitive Dimensions (CDs)– of notation– of representation in an interface– of understanding

NB. In this context a “dimension” is a factor (distinct from others factors)

Next Time• Read Edge and Blackwell, Cognitive Dimensions Tradeoffs in

Tangible User Interface Design– You find this paper by going to

www.cl.cam.ac.uk/~afb21/CognitiveDimensions– Then choosing the link for the 10th Anniversary Workshop on CDs

research• Create a concept map relating the ideas of the paper to one

another– Use the concept map software– Make sure you include at least 12 concepts and maybe many more– Consult the papers by Thomas Green for more information

• Research project presentation

Research Team Meetings

Modeling Actions

• Task analysis: temporal (time) issues• GOMS analysis: method (how to) issues• Keystroke level analysis: operator (widget)

issues

Theory Collection

Visual processing• Three-stage visual system• Preattentive processing theory (Triesman &

Gormican)• Structured object perception theory

(Biederman)• Scientific color theory (CIE)

Theory Collection (2)

Motor Behavior Models• Hick-Hyman Law: choice time• Keystroke-Level Model: error-free task

completion time• Three-state model of graphical input (Buxton)• Fitts’ Law: human movement• Guiard’s Model of Bimanual Skill

Theory Collection (3)

Models of Computation• Finite state machine• Grammar in Backus-Naur form (BNF)

Theory Collection (3)

Task analysis• Describes the process the user chooses to

reach a goal in a specific domain• Hierarchical model using ConcurTaskTreesDesign principles• GUEPs• Cognitive Dimensions• Mental models