Usability design is more challenging as products and systems are getting sophisticated with increased numbers of functions. Product interface must be designed with understanding of the users’ cognitive capabilities and prior knowledge.
Cognitive Walkthrough is the representative evaluation methods to fined usability problems considering the required mental process of users. However Cognitive Walkthrough requires relatively more effort and time to conduct compared to other expert evaluation methods. Also the findings are often hard to be formally documented. To overcome these limitations, this thesis suggests a new method which utilizes Interaction Flow Diagram (IFD). The Diagram helps to identify and document the potential user’s cognitive problems systematically by explicitly describing the sequences of tasks. The flow structure depicted by IFD can be used to suggest the set of likely usability problems at each point of the flow. Therefore this method can reduce considered usability evaluation factors of evaluation and help not to overlook essential usability problems. Through analyzing usability problem pattern based on IFD, this method help to find usability problems of other interface and tasks.
This thesis shows with real cases how the proposed method support the evaluators to conduct cognitive walkthrough efficiently from the user’s point of view without overlooking essential usability points.
