Textbook of Usability

The cognitive walkthrough, developed by Lewis, Polson, Wharton, and Rieman (1990), is an expert review method that focuses specifically on learnability — whether a new user can figure out how to complete a task without prior training. The evaluator traces the steps required for a specific task and, at each step, asks four questions:

1. Will the user try to achieve the right effect? (Does the user's goal match what the interface requires?)
2. Will the user notice that the correct action is available? (Is the control visible and recognisable?)
3. Will the user associate the correct action with the desired effect? (Does the label/icon/affordance suggest the right action?)
4. If the correct action is performed, will the user see that progress is being made? (Is feedback adequate?)

Any step where the answer to one or more questions is "no" represents a learnability problem. The four questions correspond to Norman's design principles: visibility, affordance, mapping, and feedback.

Strengths: focuses specifically on first-use experience; forces evaluator to adopt the user's perspective; can be applied to paper prototypes; identifies specific points of failure.

Limitations: time-consuming (each task walked step by step); narrow focus (only the tasks analysed); assumes a specific "correct" path; does not address efficiency or satisfaction for experienced users.

The method is most appropriate when learnability is a primary concern — systems used by new or infrequent users, walk-up-and-use kiosks, or self-service interfaces.