HCI 8) Evaluation

Question 1

Heuristic

Answer 1

Rule for evaluating a user interface. Used to detect usability problems.

Question 2

Nielsen’s heuristics

Answer 2

• Visibility of system status
• Match between system and real world
• User control and freedom
• Consistency (external/internal)
• Error prevention
• Recognition over recall
• Flexibility and tailoring
• Aesthetic and minimalist design
• Error recovery
• Help and documentation

Question 3

Heuristic evaluation -
Drawbacks

Answer 3

• Limited scope
• High false positive/negative rates
• No guarantees: unreliable nor generalizable
• High variability

Question 4

GOMS task analysis

Answer 4

• Goals: user aims
• Operators: interface actions (e.g. clicking)
• Methods: sequences of operators/sub-goals to achieve goal
• Selection rules: rules to choose particular method

Question 5

KLM-GOMS: Keystroke-level model

Answer 5

Predicts task completion times by summing up execution times for different operations needed to perform the task.

Question 6

Limitations of KLS-GOMS

Answer 6

• Assumes error-free expert behaviour
• Assumes reliable fixed time estimates are available for all operators

Question 7

Experiments -
Purpose

Answer 7

Used to test hypotheses: causal links between a manipulated change in independent variables and measured outcomes in dependent variables.

Question 8

Experiments -
Research Process

Answer 8

Design of experiment starts with formulation of a research question (empirical, constructive, conceptual)

Question 9

Experiments -
Research Hypothesis

Answer 9

Question redefined into a hypothesis, a statement that links changes in independent variables to resulting measured changed in dependent variables.

Should be testable, concise and name key constructs.

Question 10

Other evaluation methods

Answer 10

• Field evaluation of prototypes
• Pilot studies
• Deployment studies
• Think-aloud studies