Methodology and ExplanationXX50125

Lecture 3: Usability testing

Dr. Danaë Stanton Fraser

Methodology and Explanation 2005

Lectures

1. Introduction to Methods

2. Experiments

3. Interviews/questionnaires/surveys

4. Usability testing

5. Ethnography

Methodology and Explanation 2005

“Know thy user” Hansen (1971).

Methodology and Explanation 2005

What is Usability Testing?

Usability testing is a systematic approach to evaluating user performance in order to inform design.

Designs should be: • Based on observation of users• Refined by thoughtful analysis of the frequency and

sequences in which tasks are carried out• Validated through early prototype, usability tests• Direct interaction with users during the design phase

and throughout the system lifecycle

Methodology and Explanation 2005

The Move towards Usability Testing

• Traditionally, computer programmers designed for computer programmers

• When competitive products provide similar functionality usability testing is important for product acceptance

• Karat (1994) at IBM reported up to $100 payoffs for each dollar spent on usability, with benefits in reduced program-development costs, reduced programme maintenance costs, increased revenue due to higher customer satisfaction, and improved user efficiency and productivity

• Iterative design allowing for early testing of prototypes, revisions based on feedback and then incremental refinements

Methodology and Explanation 2005

Design is a process..

Example :Designing Games

• Interdisciplinary team – audio and visual design, programming, project management etc…

• Iterative design process

• cost benefits

• does design process prevent creative coding?

• Design process should be a shared vision that is built upon

Example:Designing Games

• A videogame takes approx. 30 to 36 months from inception to market. A Pre-production phase (prototyping) will generally take 12 months plus, and if it meets approval, will get funded for full development

• A PS2 videogame in the US will typically have a team of 50 plus people working on it, and will cost $5m plus (Jeffery, 2003, Lucas Arts)

Methodology and Explanation 2005

Usability Testing and Laboratories

• Emerged since the early 1980’s • To conduct usability tests of products • To provide expert reviews • Usability testing often found to increase speed of

projects and produce cost savings• Usability tests are designed to find flaws in user

interfaces• Includes set of tasks, fewer participants than

experimental study and a report of recommended changes.

Methodology and Explanation 2005

Typical procedure

Usability staff:

• Participate in early task analysis/design review

• Provide information on software tools, literature

• Develop set of tasks for testing (numbers, types of participants)

• Pilot test

• Voluntary participation with informed consent

• Think aloud technique

• Video recording

• Results feed into redesign

Methodology and Explanation 2005

Example Lab

• Each lab is separated into two sections: the Observer side and the Participant side.

• Usability Engineers sit on the Observer side, while participants are on the Participant side.

• The two sections are separated by a sound-proof wall and a one-way mirror (image below).

Microsoft

Methodology and Explanation 2005

A mixed video set-up

Methodology and Explanation 2005

Many types of Usability Testing

• Discount usability testing• Field tests• Paper prototypes• Can-you-break-this• Competitive usability testing

Two main limitations:• Emphasises first time use• Limited coverage of features

• Therefore often supplemented with expert review

Methodology and Explanation 2005

Expert Reviews

• Heuristic evaluation

• Guidelines review

• Consistency inspection

• Cognitive walkthrough

• Formal usability inspection

Methodology and Explanation 2005

References

• Dumas, J. S. and Redish, J. C. (1999). A Practical Guide to Usability Testing. Exeter, UK.

• Karat, C-M. (1994). A business case approach to usability. In Bias, R and Mayhew, D (Eds). Cost-Justifying Usability, Academic Press, New York, 45-70.

• Nielsen, J. (1993). Usability Engineering, Academic Press., New York.

• Schneiderman, B. (1998). Designing the user interface: strategies for effective human computer interaction, Addison Wesley