The cognitive walkthrough is an ideal way to identify problems that users will have when they first use an interface... by exploration rather than by reading the manual.
Although a usability problem has been identified and is recorded, redesign suggestions are not made at this point.Both cognitive walkthrough and heuristic approach are the methods of identifying usability problems. When I first came across these theories, I like the latter more for the reason that the results extracted from the former are subjective and sometimes abstract. Now I prefer cognitive walkthrough as its principle is based on asking questions to distil usability problems from users' experiences, while heuristic evaluation seems like guidelines for the designers and analysts.
The cognitive walkthrough involves the happy path and 4 questions to be asked before, during and after each step in the happy path.
the happy path
- A complete, written list of the actions/steps needed to complete the task with the interface — the ‘happy path’.
- If the happy path was too complicated, you've found a serious usability problem already. It would not make users happy at all.
4 questions
- Will the customer realistically be trying to do this action?
If the participants were trying to do something deliberately and inconsistent with their inital intention, the design may not be based on users' background knowledge and expect some unnatural actions from user. - Is the control for the action visible?
- Is there a strong link between the control and the action?
This question highlights problems with ambiguous or technical terms, or with other controls that looks like a better choice. - Is feedback appropriate and does the action prompt users to make progress towards the next step in the task?
The feedback might be missing, or easy to miss, or too brief, poorly worded, inappropriate or ambiguous.
or Streamlined cognitive walkthrough, a cut-down version not documenting problem-free steps and combining the four original questions into two:
- Will people know what to do at each step?
- If people do the right thing, will they know that they did the right thing, and are making progress towards their goal?
(Source: The 4 questions to ask in a cognitive walkthrough by David Travis, Designing Interactive Systems by David Benyon)
