Chapter 41 Flashcards
PoHCI, week 6 (8 cards)
Name some different approaches to analytic evaluation
Heuristic evaluation
Human error identification method
Cognitive walkthrough
Keystroke-level modeling
Automated usability evaluation
Briefly explain heuristic evaluation
In a heuristic analysis of an interface, an evaluator is provided a set of heuristics (rule-of-thumbs) and the interface. The task is used to detect breaches of the heuristics; in this case, the heuristics serve as
the yardstick for the evaluation
It captures theories and practitioners’ experiences in what causes problems in interaction
- List the steps to conduct a typical operation
- Focus on the interactions with the system
- Apply rules of thumb and guidelines to assess
- (Count and classify violations (critical/important/nuisance))
What are some benefits and drawbacks of heuristic evaluation?
Pros: Cheap, fast, and easy
Cons: Error prone, not exhaustive, not user-centered
High efficiency: Some usability problems can be spotted with little effort and experience
Limited scope: Heuristics are limited to aspects of usability that can be attributed to visible parts of the
UI
High false positive and false negative rates: Many important problems are not found, and some
problems are identified that are not problems
No guarantees: The results cannot be trusted to be comprehensive, reliable (large variability), nor
generalizability
High variability: Evaluators, even experienced, show drastically varying hit rates
Briefly explain cognitive walkthrough
An analytical evaluation method based on mental simulation of the way users think.
An artifact is inspected systematically, in a step-by-step manner, and evaluated against criteria.
The goal is to expose possible problems impairing the ease-of-use and learnability of a system.
Which questions does cognitive walkthrough attempt to explain?
- Will the user try to achieve the right effect?
- Will the user notice the availability of the correct?
- Will the user associate the correct action with the intended effect?
- If the correct action is performed, will the user be aware that the task is progressing as intended?
Briefly explain keystroke-level modeling
Keystroke-level model (KLM) is a simple mathematical model to assess the performance of tasks. In
particular, it can predict task completion time of experienced users.
KLM analyses user’s task to find the most likely way of accomplishing it.
This task performance is broken down according to three categories of operations: physical, mental
and system. Operations are counted and the Task completion time is calculated
What is GOMS?
A comprehensive cognitive model for human-computer interaction
Goals: What the user wants to accomplish
Operators: Basic actions users can perform
Methods: Sequences of operators to achieve the goal
Selection rules: How users choose between methods
Briefly explain automated usability evaluation
An evaluation tool to encapsulate some yardstick for good interaction, eliminating the need for an
evaluator.
