SIMS 213: User Interface Design & Development

Marti HearstThurs, Jan 29, 2004

Discussion

Kent Sullivan, The Windows 95 User Interface: A Case Study in Usability Engineering, CHI 1996.A case study of the iterative design process.

Sullivan Case Study

– 12 people on the Windows 95 team!!– Waterfall design method (compartmentalized; UI done at the

end during quality assurance stage) would produce an unusable product.

– Method:• Find most common tasks, and test on those• Compare to a baseline (Windows 3.1)• Rapid prototyping tools• Importance of usability testing!!

– Stepping back• Found big problems• Held a retreat to radically re-think things

Sullivan Case Study

– Decided to:• Focus on scaffolding (beginner -> intermediate-expert)• Give up on too much backwards-compatibility with 3.1• Dump the huge design spec (!) Encouraged social interaction.• Continually informed outsiders as well as team members about the

design– Fine tuning with usablity tests

• Holistic interface test in the lab– Many participants!

• Longitudinal field study– About Windows 3.1

• … a good demonstration of what happens when usability is not taken into account

Readings for This and Next Lecture

Cooper (Inmates, Chs. 9-11)

Constantine & Lockwood Ch. 5

Newman & Landay article

Slide by James Landay

Why User-Centered Design?

System will fail if it:– does not do what the user needs– is inappropriate for the user

Why don’t we just define what a “good interface” is?– There is a huge variety of users and tasks– Guidelines are usually too vague

e.g. “Provide feedback”, “Be intuitive”

Slide adapted from Ben Shneiderman

Participatory Design

A subset of user-centered designUser actively participates in design of the systemPros:– 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

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

User-Centered Design OverviewNeeds assessment– Find out

• who users are• what their goals are• what tasks they need to perform

– Task Analysis• Characterize what steps users need to take• Create scenarios of actual use• Decide which users and tasks to support

Design based on thisEvaluation– Test interface by “walking through” tasks– Do this before implementation

Slide by James Landay

Caveats

Politics– advocating change can cause controversy– get a sense of the organization– important to get buy-in from all those involved

Don’t design forever without prototyping– rapid prototyping, evaluation, & iteration is key to

techniqueSystems level apps are poor candidates– networking, etc.

Example: Student Course Enrollment:How to Help Students Achieve their Goals?

enroll in sims 213

learn to build useful systems

become successful IT manager

achieve lifetime of success

Help Users Achieve Goals

Example: Course Enrollment Software– What matters from the programmers’ point of view?– What matters from users’ point of view?– What about the course administrators?

User-Centered Design Example

You have been hired by Pizzas R Us (PRU) Design a system to– make online orders from the web

Also considering special features– online discount coupons– allowing party orders in advance– customer recommendations, linking to reviews– comparing local pizza parlors

User-centered Design Example

Your job: figure out– how people do their pizza ordering now– how they would like to do it online– what features would make sense when– must also take into account the needs of the pizza parlor owners

and workers. This is the needs assessment.Techniques:– Observation– Interview– Study existing successful designs

User-Centered Design Example

Observation– Visit one or more pizza parlors. Observe how people

achieve their pizza ordering goals.– Observe what the counter people need to do.

Optionally: interview these people

User-Centered Design Example

Interview– Prepare a list of questions about how people do their pizza ordering and

what they would like in an automated ordering system. – Interview at least three people about what they would like in an automated

ordering system and how they would like it to work. • Try to identify people with different needs and preferences, with respect to their attitudes

about using online ordering systems. – Ask them what, if anything, must be in the system in order for them to prefer

it over a phone ordering system or an in-person ordering system. (E.g., no busy signals, cheaper prices, comparison shopping, faster service, or would they

prefer anything over current methods.)

– Go look at at least one existing on-line food ordering web site and see how they handle these tasks.

User-Centered Design Example

Consider existing designs– Look at least one existing on-line food ordering web

site and see how they handle these tasks.

User-Centered Design Example

Procedure– Answer the needs assessment questions– Try to understand the basic tasks that are currently supported

within pizza parlors and via phone orders– Make a table showing

• user types• tasks• (guesses about) relative frequencies of tasks

– Decide which of the new tasks customers may perform using the new interface.

• Make note of which ideas you decided to drop based on your interviews.

Slide adapted from James Landay

Needs Assessment Questions

Who is going to use the system?What tasks do they now perform?What tasks are desired?How are the tasks learned?Where are the tasks performed?What is the relationship between the user and the data?

Slide adapted from James Landay

Needs assessment Questions

What other tools does the user have?How do users communicate with each other?How often are the tasks performed?What are the (time) constraints on the task?What happens when things go wrong?What happens when things go wrong?

Slide adapted from Ben Shneiderman

Task Analysis

Characterize what happens when users perform typical tasksTools:– table of user communities vs. tasks

• Who x What– table of task sequences– flowchart or transition diagram– videotape depicting scenario

Slide adapted from James Landay's

How Often Do Users Perform the Tasks?

Frequent users remember more detailsInfrequent users may need more promptingWhich function is performed– most frequently?– by which users?– optimize system for tasks that will improve

perception of its performance

Augment Table with Percentages(What percentage of the is this task done by this person)(Numbers are only suggestive, adapted from Shneiderman 98)

J ob Title Query by Patient Update Data Query acrossPatients

Add Attributes

Nurse 14% 11%

Physician 6% 4%

Supervisor 1% 1% 4%

Appointmentadministrator

26%

Clinical researcher 8%

Databaseprogrammer

2% 2%

User-Centered Design Example

Scenarios– Create three scenarios that will exercise these tasks

in the proposed interface– Create a description in which you outline

• A person’s background• Their goal(s)• How they achieve these goals using the steps in the

system– Note: this will change a bit when we use personas

User-Centered Design Example

Sketch an initial design– Explain how the pizza ordering system will work.

• Either a textual description or a flow chart (or both) showing the sequences of steps that will be allowed in the system.

• Provide rough sketches showing at least three of the important screens.

– Walk through at least one of the scenarios you developed and show how it can be handled by the interface.