Methodology and Explanation XX50125 Lecture 2 Part 1: Usability testing Part 2: Interviews and questionnaires Dr. Danaë Stanton Fraser.

Methodology and ExplanationXX50125

Lecture 2Part 1: Usability testing

Part 2: Interviews and questionnaires

Dr. Danaë Stanton Fraser

Methodology and Explanation 2007

Lectures

1. Introduction to Methods

2. Experiments

3. Usability testing

4. Interviews/questionnaires

5. Ethnography


“Know thy user” Hansen (1971).


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


The Move towards Usability Testing

Traditionally, computer programmers designed for computer programmers

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


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

• When competitive products provide similar functionality usability testing 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.


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)


Usability Testing and Laboratories

• Emerged since the early 1980’s • To provide expert reviews • To conduct usability tests of products • 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.


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


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


Expert Reviews

• Heuristic evaluation• Guidelines review• Consistency inspection• Cognitive walkthrough• Formal usability inspection


Part 2: Interviews and questionnaires


Why Interview?

• Good for obtaining information about– Opinions– Feelings– Goals (organisational, personal and system)– Things you didn’t know you needed to know

• Bad for gathering (large volumes of) data


Interview Preparation

• Decide objectives• Read background material• Decide whom to interview• Set up the interview• Decide interview structure• Write down questions you will ask and pointers for

questions you might ask


Open Questions

E.g. “How do you find using this technology in your lectures?”

• Little control• Hard to analyse • Hard to keep focussed on interview objectives• May unsettle interviewee• Time consuming and can be difficult to analyse

However:• May gain more depth, rich data• May tell you things you had not considered• May give you ideas for future projects


Closed Questions

E.g. “How many courses do you teach?” “How many times have you used this technology?”• May settle interviewee• Easy to analyse• Easy to maintain focus• Observation and use of data may be more efficient

However:• Data may not be as rich


Question Pitfalls

• Leading questions– “How bad is the current system?”

• Double questions/poor structure– “How often does the system fail, and how do you

fix it when it does?”

• Stay focussed. If you are unlikely to be able to make use of the answer don’t ask the question!


Question Structure

• Pyramid

– Start with closed questions, finish with open

– Good for settling nervous interviewees as answers are ‘easy’ early on

• Funnel

– Start with open questions, finish with closed

– Good for aggressive interviewees as opinions are asked for early on• Diamond

– Closed -> Open -> Closed, Good all-round technique• Structured/unstructured

– All interviews may vary depending on how focused you intend to be on the prepared structure


Starting the Interview

• Dress• Greeting – first time

– Who you are – Why you want to interview them– What objectives you want to achieve from the interview– That the information they give is confidential and how it

might be used• Subsequent greetings should discuss an issue from or

summarise the previous interview• Don’t just “be yourself”


During the Interview

• Introduce each line of questioning

• Probing

– E.g. “Why?”

– Shows that you are listening

– Good for keeping interview focus

– Double-check information and notes• Taking notes

– Not too many

– Maintain eye contact

– Go back over important points• Use of sound recorders


Focus Groups

• Normally 3-10 people

• A representative sample of typical users

• Enables people to put forward ideas in a supportive environment

• Facilitator guides and prompts

• Discussion recorded

• Low-cost but need good facilitator


Questionnaires

• For wider coverage

• Need to know the right questions (through interviews and background)

• Focus on objectives

• Don’t ask unnecessary questions

• Keep it short and facilitate response

• Open and Closed questions

• Scaling


Likert Scale

• Short statements about the features to be evaluated

• Divide the items into groups with same number of positive and negative statements in each group

• Decide on scale – even or odd, number of points

strongly agree

agree neutral disagree strongly disagree


Questionnaire difficulties

• The ‘halo effect’– Respondent answers everything the same by not

differentiating between questions– Mix questions up on different subjects

• Leniency– Some respondents rate everything too well– Move the ‘average’ category left (or right) of centre and

make scale descriptors stronger• Central tendency

– Respondents rate everything as average– Increase the number of points on the scale and adjust the

scale descriptors to cover a smaller range of opinions


Also…evaluation during active use

• System refinement as a result of experience or in response to changes in users

– interviews and focus group discussions

– continuous user-performance data logging

• look at both frequent and infrequent error messages

• analyse sequences of actions to suggest improvements or new actions

• BUT respect people’s rights and consult them first!

– User feedback mechanisms

• on-line forms, email and bulletin boards

• workshops and conferences


Preparation for Practical

Methodology and Explanation XX50125 Lecture 2 Part 1: Usability testing Part 2: Interviews and questionnaires Dr. Danaë Stanton Fraser.

Documents

competitive usability

rich slide

ethnography slide

system lifecycle slide

expert review slide

testing numbers

lucas arts slide

cost savings usability