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