Seng 5115 spring 2011
1 / 29

Seng 5115 Spring 2011 - PowerPoint PPT Presentation

  • Uploaded on

Seng 5115 Spring 2011. Usability Testing. Usability Testing: A Systematic Look. The big picture. Why are you conducting the test? What are you going to learn? What will the results be used for? What kind of claims do you want to make?

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Seng 5115 Spring 2011' - alodie

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Seng 5115 spring 2011

Seng 5115Spring 2011

Usability Testing

The big picture
The big picture

  • Why are you conducting the test?

  • What are you going to learn?

  • What will the results be used for?

  • What kind of claims do you want to make?

  • ROI: Your time and users’ are valuable

Two broad approaches

Caveat: these columns are not carved in stone

Two broad approaches

More specifically different methods

Our focus so far (and today)

More specifically, different methods

  • Controlled (laboratory) experiments

  • Field experiments

  • Field studies

  • Qualitative usability studies

    • Think aloud method

What are you trying to learn
What are you trying to learn?

  • Concrete, quantitative measures of usability

    • Time to learn a feature

    • Use time for specific tasks and users

    • Features used (or not)‏

    • Error rates

    • Measures of user satisfaction

    • Comparison to prior/alternative versions, competitors

  • Results!

What are you trying to learn 2
What are you trying to learn (2)?

  • Qualitative experiences of usability

    • What will they use this thing for anyway?

    • Trouble spots in completing tasks

    • Features found / not found

    • Reactions to design elements/decisions

    • Learning users’ mental models

    • Why can’t those silly users do it?

  • Process!


  • For your prototype, brainstorm key things you would want to learn

Picking users
Picking users

  • Hopefully, real users

    • Variety

    • Authenticity: definitely not your group

  • Gosh, how many?

    • Key point: users’ time is valuable

    • Diminishing returns (especially formative)‏

  • Recruitment

Picking tasks
Picking tasks

  • Tasks vs. play (exploration)‏

  • Scripts for tasks

    • A lot like scenarios

    • When is the task over?

  • How long can tasks be?

  • What tasks should you choose?

Which tasks
Which tasks?

  • Common tasks

  • Potentially troublesome tasks

  • Aspects of the design with many options

  • Tasks your prototype supports!

    • Horizontal vs. vertical prototyping

    • The Wizard of Oz

What data to collect
What data to collect?

  • Observations, notes

    • Videotape?

  • Pretests

    • To gauge/control for experience level

  • Questionnaires

    • Multiple choice vs. open-ended questions

  • Process data

Think aloud method
Think aloud method

  • User asked to think aloud

    • ask questions (they won’t be answered)

    • explain decisions, identify confusion

  • Very useful for understanding

Setting up the environment
Setting up the environment

  • “Natural” use scenario

  • Eliminate distractions

    • (unless distractions are part of the test!)‏

  • Space between user and experimenter

  • Facilities for observers and data collection


  • Experimenter

  • Observer / Data Collector

The experimenter
The experimenter

  • Oversees the testing process

    • Makes sure setup is ready

    • Welcomes users

    • Conducts test activities

    • Debriefs subjects

  • Better to not collect data

    • Let observers do this

Experimenters very important
Experimenters: very important

  • Practice!

  • Be consistent

  • Don’t “help” or interfere with tests

    • Very tempting…

    • But keep ethics in mind

  • Be aware that testing can affect you

Pilot study very important
Pilot study: very important

  • Find obvious mistakes

    • Hopefully, Cognitive Walkthrough and Heuristic Evaluation helped here

  • Get practice running tests

  • Check that tasks are realistic

  • Gain confidence in data collection

  • Pilot study likely to change test plan

Running a test with one user
Running a test with one user

  • Preparation

  • Introduction

  • Scripts

  • Debriefing

Running preparation
Running: Preparation

  • Room ready?

  • Equipment ready?

  • Interface in the start state?

  • Observers present?

    • One experimenter, several observers

  • Other needed materials available?

Running introduction
Running: Introduction

  • Evaluating the interface, not the user

  • No personal stake

  • Confidentiality reminder -- system,results

  • Voluntary participation

  • Welcome to ask questions

  • Specific instructions

  • Any questions?

Running scripts
Running: Scripts

  • Introduce each task

    • Go over task with subject

    • Ask for questions

  • Refrain from interacting with the subject

    • “Help”ing doesn’t

    • Prompt for thinking aloud, if needed

    • Watch for stuckness: wait, hint, skip, fail

Running debriefing
Running: Debriefing

  • Administer questionnaires

  • Ask follow-up questions

  • General discussion

  • Any other comments?

  • Thank them!

  • Team debrief?

Interpreting the data
Interpreting the data

  • Some way of prioritizing

    • Severity

    • Number of observers who record problem

    • Ease of fixing

  • Summarizing the results

    • A report

    • More on this later

  • Note: Keep a design focus!

    • Or you may be analyzing for months….

General guidelines
General Guidelines

  • Always have a pilot study

  • Get professional help for big studies

  • In general, it is better if you aren’t there

    • too much bias

    • subtle clues (the counting horse)‏

    • stay behind one-way glass

    • (but, realistically….)‏

Test plan checklist 1
Test Plan Checklist, 1

  • Goal of the test?

  • Specific questions you want to answer?

  • Who will be the experimenter?

  • Who are the users going to be?

  • How many users are needed?

  • What kind of instruction will users be given?

  • What tasks will you ask the users to perform?

  • What criteria will be used to determine the end of each task?

A test plan checklist 2
A Test Plan Checklist, 2

  • What aids will be made available to users?

  • To what extent will the experimenter be allowed to help the users?

  • What data is going to be collected and how will it be analyzed?

  • What is the criterion for judging the interface a success?

A test plan checklist 3
A Test Plan Checklist, 3

  • Where and when will the evaluation be done?

  • How long will the evaluation take?

  • What computer support?

  • What software?

  • Initial state of the system?

  • Are there any system/network load requirements?