User Interface And Design

Front 1

Goals of Evaluation

Back 1

- Access extent of system functionality
- Determine the effect of interface on user
- Identify specific problems with design

Front 2

Evaluation methods

Back 2

- Empirical
- Analytical
- Physiological

Front 3

Why are evaluation utilized?

Back 3

- Evaluation is necessary to iterate products
- Problems if safety and usability issues are unresolved
- Useful for work and research environments

Front 4

Empirical Methods (Formative and summative)

Back 4

- Observation
- Think-alouds
- Interviews
- Questionnaires

Front 5

Evaluation (Formative)

Back 5

- Goal is to refine and formulate the design
- Occurs in the design-evaluate-redesign phase
- Less structured testing, goal is to learn

Front 6

Evaluation (Summative)

Back 6

- Goal is to assess the impact, usability and effectiveness
- Occurs after system has been developed
- More structured testing, goal is to measure

Front 7

Analytical Methods (Formative)

Back 7

- Heuristic evaluation
- Cognitive walkthroughs
- Predictive Techniques

Front 8

Cognitive Walkthroughs

Back 8

Advantages
- Finds task-oriented problems
- Helps define users’ goals and assumptions

Disadvantages
- Time-consuming
- Training required
- Applies only to ease of learning problems

Front 9

Cognitive Walkthroughs (Question Format)

Back 9

Will the user know what to do?
Will the user know how to do it?
Will the user understand from feedback whether the action was correct or not?

Then record this information in a table

Front 10

Heuristic Evaluation

Back 10

- Guidelines to make or critique a design decision
- Good for debugging early design
- Discount usability technique
- Performed by 3-5 evaluators independently
- Discovery of about 75% of usability problems

Front 11

Heuristic Evaluation (Nielsen recommended)

Back 11

- Visibility of system status
- Match between system and real world
- User control and freedom
- Consistency and standards
- Error prevention
- Recognition rather than recall
- Flexibility and efficiency of use
- Aesthetic and minimalist design
- Help users recognize, diagnose, recover from errors
- Help and documentation

Front 12

Expert Evaluation - HE

Back 12

Advantages
- Few ethical & practical issues to consider because users not involved
Can be difficult & expensive to find experts
- Best experts have knowledge of application domain & users

Disadvantages
- Important problems may get missed
- Many trivial problems are often identified
- Experts have biases

Front 13

Predictive Models

Back 13

- No actual test on users
- Predict user performance with interfaces
- E.g. predicting how fast users can enter data into a system
- Can also be used when user testing is not possible

Front 14

Eye tracking (Predictive Models)

Back 14

- Head or desk mounted equipment tracks the position of the eye
- Eye movement reflects the amount of cognitive processing a display requires

Front 15

Evaluations (Laboratory studies vs Field studies)

Back 15

Laboratory - Consistent, Not as Realistic, Biased?
Field - Not as Consistent, Realistic, Biased?

- Reliability
- Validity
- Bias

Front 16

DECIDE: a framework to guide evaluation

Back 16

- Determine the goals - Who, what, why
- Explore the questions.
- Choose the evaluation approach and methods - Formative vs Summative/Analytical vs Empirical/Qualitative vs Quantitative data
- Identify the practical issues - Users, budget, schedule.
- Decide how to deal with the ethical issues. - Consent form
- Evaluate, analyze, interpret and present the data. - Reliability, validity, bias