User Centered Design and Task Analysis Marti Hearst (UCB SIMS) SIMS 213, UI Design & Development January 28, 1999

Ripped from the Headlines l Jan 28, 1999, New York Times “On-Line Trades Rise and So Do the Complaints” –Internet investor places an order for a stock he thinks will cost between $ Buys 2,300 shares at $90 each!! –Internet investor places an order to sell 30 shares, never got e-confirmation, replaced order, sold 60 shares l What is the problem?

Ripped from the Headlines l Investors have erroneous mental model of how e-trade works –mistakenly assume timing is the same for non-professionals as for brokers –assumptions about when/what a confirmation is l Interfaces not providing adequate and appropriate feedback –Warning messages on web sites is not sufficient

Today l Administrivia –Textbook –Class Accounts/Enrollment –More on Projects/Timeline l Individual Differences l User-Centered Design (cont.) l Task Analysis (intro)

Lecture Topic Schedule (Tentative) l 1 Intro to HCI; Current Uis l 2 Design Cycle, Affordances, User-Centered Design l 3 Task Analysis l 4 Human Abilities l 5 Design Guidelines/Heuristic Evaluation l 6 Prototyping l 7-8 Interaction Models (Midterm) l 9 Web Design/Search Interfaces l 10 Information Architecture/Navigation l 11 User Testing l 12 Innovative UIs l 13 Graphic Design/3D UIs l 14 Personality/Social Aspects/Agents l 15 Class Presentations

Topic and Assignment Schedule (Tentative 1/28/99) Week numbers indicate assignment due dates There may be an additional assignment l 1 Intro to HCI; Current UIs l 2 Design Cycle, Affordances, User-Centered Design l 3 Task Analysis (Indiv Project Proposal) l 4 Human Abilities (Task Analysis Assign., Project Assign.) l 5 Design Guidelines/Heuristic Evaluation (Project Task Analysis) l 6 Prototyping (Interface Sketch, HE Assign) l 7-8 Interaction Models (Midterm) (Lo-fi Prototype, Midterm) l 9 Web Design/Search Interfaces (Work on Interactive Prototype) l 10 Information Architecture/Navigation (Interactive Prototype) l 11 User Testing (Project Heuristic Evaluation) l 12 Innovative UIs (Second Interactive Prototype) l 13 Graphic Design/3D Uis (Pilot User Study Description) l 14 Personality/Social Aspects/Agents (Pilot User Study) l 15 Class Presentations (Third Prototype, Presentations )

Slide adapted from Saul Greenberg Individual Differences l You do not necessarily represent a good average user of equipment or systems you design l Do not expect others to think or behave –as you do –as you would like them to l People vary in thought and behavior just as they do physically

Playing Pictionary Getting into someone else’s head

Slide adapted from Ben Shneiderman Accommodation of Human Diversity l Physical abilities and workplaces –Differences in height, reach –Dynamic measurements: strength, speed –Account for variances in sense perception »vision: depth, contrast, color blindness, motion sensitivity »hearing »touch

Slide adapted from Ben Shneiderman Accommodation of Human Diversity l Cognitive and Perceptual Abilities –memory –problem solving and learning –decision making –search and scanning –time perception l Dynamic Physiological-Affecting Factors –sleep deprivation/fatigue –anxiety/fear –drugs and alcohol –circadian rhythms

Slide adapted from Ben Shneiderman Accommodation of Human Diversity l Personality differences (Nass et al.) l Cultural and international identity l Users with disabilities l Elderly Users

Slide adapted from Saul Greenberg Diversity in Roles noviceswalk up and use systems interface affords restricted set of tasks tutorials for complex uses casualstandard idioms recognition over recall reference guides interface afforts basic task structure intermediateadvanced idioms complex controls reminders and tips interface affords advanced tasks expertshortcuts for power use interface affords full task + customization kiosk WWW most shrink- wrapped software custom software

Slide by James Landay What is User-centered Design? l Developers working with target users l Think of the world in users’ terms l Understanding work process –points where humans and computers intersect l Not technology-centered/feature driven

Slide by James Landay What is Usability? l Ease of learning –should be faster the second time and so on... l Retention over time –remember how from one session to the next l Productivity –perform tasks quickly and efficiently l Minimal error rates –if they occur, good feedback so user can recover l High user satisfaction –confident of success TTN

How to Involve the User l Ethnographic Observation l Participatory Design l Scenario Development

Slide by James Landay Understanding the User l How do your users work? –task analysis, interviews, & observation l How do your users think? –understand human cognition –observe users performing tasks l How do your users interact with UIs? –observe!

Slide adapted from Ben Shneiderman Ethnographic Observation l Observe; do not intervene l Try to avoid preconceptions l General approach: –Preparation –Field Study –Analysis –Reporting

Slide adapted from Ben Shneiderman Ethnographic Observation l Preparation –Get acquainted with organization’s policies and work culture –Gain access and permission to observe –Set initial goals l Field Study –Establish rapport with managers and users –Observe/Interview users in workplace –Collect data »subjective/objective »qualitative/quantitative

Slide adapted from Ben Shneiderman Ethnographic Observation l Analysis –Quantify and compile the collected data –Reduce and interpret the data –Refine goals and process based these l Reporting –Consider multiple audiences and goals –Prepare report and present findings

Slide by James Landay Participatory Design l Users help designers learn –what is involved in their jobs –what tools they use –i.e, what they do l Developers reveal technical capabilities –builds rapport & an idea of what is possible l Users try prototype & comment on it –developers make incremental changes & iterate

Slide adapted from Ben Shneiderman Participatory Design l User actively participates in design of the system l Pros –potentially more accurate information about the tasks –more opportunity for users to influence the design decisions –buy-in from sense of participation –potential greater acceptance of final system

Slide adapted from Ben Shneiderman Participatory Design l Cons (potential) –more costly –lengthier implementation period –antagonism from those whose suggestion are not incorporated –force designers to compromise design –exacerbate personality conflicts between designers and users –highlight organizational politics

Slide by James Landay Participatory Design Observation Techniques l In the work place l Use recording technologies –notebooks –tape recorders –video cameras l Ask users to think out loud while working –look for job-specific procedures / terminology l Show users transcript & ask about it

Slide by James Landay What Users Might Say l?l? l “This is too difficult” l “You don’t have the steps in the order we do them” l Do not take comments personally –you shouldn’t have a personal stake l Goal is to make the system easy to use for your intended users

Slide adapted from Ben Shneiderman Scenario Development l Characterize what happens when users perform typical tasks l Tools: –table of user communities vs tasks –table of task sequences –flowchart or transition diagram –videotape depicting scenario »This leads us into Task Analysis

Slide by James Landay Caveats l Politics –advocating change can cause controversy –get a sense of the organization –important to get buy-in from all those involved l Don’t design forever without prototyping –rapid prototyping, evaluation, & iteration is key to technique l Systems level apps are poor candidates –networking, etc.

Task-Centered Design Reading: Textbook, Chapter 7

Slide by James Landay Outline l Example (E-Commerce) l Overview of Task Analysis l Why do Task Analysis? l How to do a Task Analysis l Selecting Tasks l Using Tasks in Design

E-Commerce Web Sites l Encourage and allow users to –shop –purchase –learn about the company l Compare poorly and well-designed sites –Back to Basics Toys –ToySmart –Red Rocket

Task Analysis Overview l Identification –Find out »who users are »what tasks they need to perform –Observe existing practices –Create scenarios of actual use l Design –Decide which users and tasks to support –Design based on this l Evaluation –Test interface by “walking through” tasks –Do this before implementation

Slide by James Landay Why Task Analysis? l System will fail if it –does not do what the user needs –is inappropriate to the user l Why don’t we just define what a “good interface” is? –Infinite variety of users and tasks –guidelines are usually too vague »e.g. “Provide feedback”, “Be intuitive”

Slide by James Landay Task Analysis Questions l Who is going to use the system? l What tasks do they now perform? l What tasks are desired? l How are the tasks learned? l Where are the tasks performed? l What is the relationship between the user and the data?

Slide by James Landay Task Analysis Questions l What other tools does the user have? l How do users communicate with each other? l How often are the tasks performed? l What are the (time) constraints on the task? l What happens when things go wrong?

Next Time l Complete Task Analysis Example l Characteristics of Good Task Examples l Walk-Throughs l Using tasks in design