hci
3 methods in D.E.
FOW O, Participants O, Interviews
C.M. are informed by many design elements
Metaphors, Modes, Affordances, Constraints, Mappings, Prior experiences
When is Design Ethnography(D.E.) appropriate?
Minimal knowledge of users': CURRENT PRACTICES, goals, environment, cultural background, patterns etc
Errors?
Mistakes made during task. 3 key situations: result in significant loss in EFFICIENCY, significant COST, task FAILURE
Diaries
Time diaries have a focus; could be feedback diary(for researcher), elicitation diary(to user). unstructured diaries or structured diaries
Prior Experience
Try to accommodate both novice and experts
Models lead to
action
Task success?
binary vs levels of success; 'give-up' rate(~10%)
level of abstraction in video analysis
low-level variables(time and space), mid-level mechanisms(task model and mental model), high-level processes(interaction and context)
D.E. is
observing ppl in their NATURAL SETTING for deep understanding
Learnability?
performance vs time; can use the slope or point
Self-reported metrics?
Capture using scales (Likert (agreeing)/ Semantic differential/ Rating); measure expectation vs experience; Usability magnitude estimation
C.I. what to look for?
Workarounds, mismatch between what ppl say and do, sighs, rolling of eyes etc.
3 types of U.M.
Task performance measures, subjective measures of user experience, measures of user behavior (B.O.S. as U.T. data)
In 90s what people think of 21st century computer?
Technologies disappears. They weave themselves in everyday life and become indistinguishable.
When is conducting a Cultural Probe(C.P.) appropriate?
When your users are: on the move, in unpredictable environments, not comfortable for observation
How to judge a model?
fit, simplest, consistency(internal & external), predictive value, hierarchy, final test with audience
Eye tracking include
fixations, saccades, scan paths
When to U.T.? F&S
formative and summative
Other physiologic measures
heart activity, sweat gland, muscle and brain; some data is hard to interpret
Usability vs usefulness vs desirability
how well a system SATISFIES its intended use, the value a system OFFERS to its user, how DESIRABLE the system is for its user
C.M. diff from implementation model and manifest model
i.m.: how it actually works; m.m. how it represents itself to the user(will struggle user if doesn't match C.M.)
Metaphor
'jump start', but less creative
The 3 pillars (ASE)
-> Analyze -> Synthesize -> Evaluate ->
Steps in D.E.
1. define problem 2. find people 3. plan an approach 4. collect data 5. analyze data 6. share insgiths
Execution-Evaluation model for interaction
1. establish the goal 2. form the intention 3. specify the action sequence 4. execute the action sequence 5. perceive the system state 6. interpret the system state 7. evaluate -revise-> 1.
Usability Testing 5 characteristics (first and dirty than research , not scientific)
1. goal is to improve usability 2. participants represent real users 3. participants do real tasks 4. observe and record what the participants do 5. analyze the data, diagnose the problem and try to fix it
HCI started?
40s
SketchPad special?
Ancester of CAD
Premise of C.P.? (goal)
Ask people to observe and report their own actions.
How to present data?
Bar chart, radar chars, harvey balls are effective
Behavioral measures? (3)
Clickstream, verbal behaviors, nonverbal behaviors (including facial expression, body language, physiologic pheno)
User-centered methods includes
D.E. & C.I. & C.P.
Core premise of C.I. (GOT)
Go where the customer works, Observe the customer as he or she works and Talk to the customer about the work.
Power of C.P.?
Identify temporal patterns, access environment we can't go etc
Hci is about... (IUDTM)
Identifying design problems+ Understanding user needs+ Designing interfaces+ Testing whether a design is good+ Making sure that the design meets certain goals
CONCURRENT think-aloud (T.A.) problem
Insight disruptive, use RETROSPECTIVE T.A. within hour
4 principles of D.E. (NHDM)
Natural Settings & Holism(CONTEXT) & Descriptive(ACTUALLY) & Members' PoV
Types of data in U.T.
Objective measurements, behavioral measurements, subjective measurements (B.O.T.)
What is the difference between taxonomy and TASKTONOMY?
Organized by human ACTIVITY structure instead of dictionary classification.
How to represent the models?
Tables, static diagrams, dynamic information visualization, formal grammars, pseudocode, simulation
Power of U-C M?
Understand what ppl say do and think, access experience in natural context, identify breakdowns, workarounds and frustrations
Conceptual model (mental model)
how user thinks a system work and what it mean
Artifact model
document physical ARTIFACTS
When is Contextual Inquiry(C.I.) appropriate?
CURRENT PRACTICES are better known. Little knowledge of users': breakdowns in current practices, cultural influences on work etc
How to differentiate new and old computing?
The old computing is about what COMPUTER can do, the new computing is about what PEOPLE can do.
Parts of test plan of U.T.
1. Goal 2.Research questions 3. Participant characteristics 4. Method 5. Task list 6. Task environment, equipment and logistics 7. Test moderator role 8. Data to be collected and evaluation measures 9. Report contents and presentations
Stages of U.T.
1. Plan 2. Set up the test Environment 3. Find participant 4. Prepare 5. Conduct 6. Debrief the participant 7. Analyze 8. Report
Common U.M. metrics (according to a book)
1.* task success* 2. *task time* 3. *errors* 4. *efficiency* 5. *learnability* <- B.O. | S. ->6. issues-based metrics 7.* self-reported metrics* 8. behavioral and physiological metrics 9. combined and comparative metrics
Why the user is not like me?(ICSS)
1.Designers are much more familiar with the INTERFACE. 2.Designers are CONFIDENT. 3. Designers work in different SETTINGS. 4. Designers have different SKILLS.
Interactive models
A way of describing interaction and its component parts; to help us find problem in interaction and design new interaction
Modes
Active (direct manipulation for higher engagement and shorter distance) and passive; should be VISIBLE and INVERTIBLE
4 principles of C.I. (CPIF)
Context(SETTING of participant) & Partnership(MASTER/APPRENTICE model) & Interpretation(can do checking) & Focus(THEMES)
ESM
Data captured in situ in real time
HCI is a discipline concerned with...
Design, Evaluation and Implementation of interactive computing systems for human use and with the study of major phenomena surrounding them.
Power of D.E.
Discover MEANING in ppl's lives and design products that offer meaningful experience
Task-based U.T. cautious points
Do not answer question, allow stray, give stories and tasks in order, look for CATASTROPHIC problems etc
Foundations of C.P.?
ESM(experience sampling method) or EMA(ecological momentary assessment)
Models
EVOLVES
Non-task based U.T. is
EXPLORATION, but less controlled less focus and less direct. Could be made with more users. But expensive.
Usability Evaluation (U.A.) Methods
Empirical (Usability.T. & Performance.E. & Behavior.E. & M.Satisfaction.) and Non-empirical (Cognitive.M. & H.E. & Cognitive.Walkthrough.)
Method of C.P.?
Experience sampling(diaries, disposable cameras, stickers...)
5 kinds of work models?
Flow, Sequence, Artifact, Culture, Physical
G.I. roles?(6)
Interviewers, Work Modelers, Recorder, Moderator, Participants, Rat-hole watcher
5 components of usability?
Learnability, Efficiency, Memorability, Errors, Satisfaction; first 4 are task performance measure, last is UX measure
Diary used for _____ tasks
Privacy-sensitive, Spontaneous, Mobile, Restricted access, High sampling rate
SUS?
Over 80 is good, less than 60 is poor
DRM
Overall more efficient than ESM because not disruptive but might not be correct memories
6 types of affordances (PHFCSN)
Perceptible, Hidden(bad), False(bad), Consistent, Sequential, Nested
Time of task?
Range, thresholds, distributions and outliers
Model formation
Ready-to-hand is good, present-at-hand is big breakdown
C. I. withdraw&return?
Researcher ask participant to withdraw momentarily from task at hand to discuss a question
Interaction style
The choice of LANGUAGE is determined by interaction style. e.g. WIMP(windows, icons, menus, pointing device), command line, menus, natural language, Q&A, point and click, conversation, direct manipulation etc
Method in C.I.?
Think-aloud
Interaction has properties (TCRE)
Two-way, communicative(info sent), receptive(info received), effective
Power of C.I.
Understand what they are THINKING when they are DOING
This class is about.... (UIDPE)
Understanding -> Ideation -> Design -> Prototyping -> Evaluation
What else to measure besides from TEELTS?
Visual appeal, usefulness, enjoyment, credibility, responsiveness, ease of navigation etc.
How to analyze the data?
Visualize, thresholds, mean, variance, statistics etc; Might want to segment by participants or tasks
Model is
a USEFUL theories(guess) of how things are ORGANIZED and EXPLANATION of each part of it
C.I. is
a method for gathering and representing data about the user and his/her work
Usability is
a quality attribute that assesses how EASY user interface are to use
Diary 4 key methods
diary study, C.P. experience sampling, day reconstruction method
Cultural model
document INFLUENCERS and how they influence the work of specific ppl
Flow model
document ROLES of different users and how they COMMUNICATE and COORDINATE
Sequence model
document step-by-step information on how work is done including INTENT, TIGGER and BREAKDOWNS
Physical model
document the physical ENVIRONMENT where work happens, including ORGANIZATION of space, GROUPING of people and their MOVEMENT in space.
Efficiency?
effort(cognitive and physical) vs task
Pupil dilation inplies
extreme emotional situation, load on working memory increased attention, sensory discriminations, cognitive load etc
level of abstraction
lowest to highest: coding -> model construction ->model evaluation
Heart of all design
models and modeling(= drawing and sketching)
Models as stories:
models are explained by stories; stories create models
Mappings
natural mappings to minimize instructions and help, do not do inverse mapping
video analysis coding methods
network structure and scenes
Models came from
observations
the process
open coding(concepts), axial coding(category), selective coding(CAC for relational models), comparative analysis(stories) and theory building(theories)
Affordances
perceived of an object usage, 'jump start' with an artifact in environment, want both VISIBILITY and FEEDBACK(smooth and not disruptive)
Constraints
prevent error
grounded theory process for both coding for text and video
reading a textural database, identifying interelationships
Models are for
sense-making, communication, sharing