Evaluating the usability of a cancer registry system using Cognitive Walkthrough, and assessing user agreement with its problems

Good design of cancer registry systems makes them easy to use, while poor design of their user interfaces leads to user dissatisfaction and resistance. The objective of this study was to evaluate the usability of a cancer registry system using Cognitive Walkthrough (CW) and to assess users' agreement with its usability problems.

CW was used to evaluate the registry system. We developed a checklist to help evaluators speed up the evaluation process, a problems form to collect the usability issues identified by the evaluators, and a problems severity form to determine the severity of problems by the evaluators. The problems were classified into two categories according to the CW questions and the system tasks. The agreement of the users with the system problems was examined by an online questionnaire. Users' agreement with the problems was then analyzed using the Interclass Correlation Coefficient in the SPSS 22 (Statistical Package for Social Science).

In this study, 114 problems were identified. In the categorization of problems based on the CW questions, 41% (n = 47) of the problems concerned the issue of "users do not know what to do at each stage of working with the system", 24% (n = 27) were classified as "users cannot link what they intend to do with system controls", and 22% (n = 25) were related to "user's lack of understanding of the system processes". Based on user tasks, about 36% (n = 41) of the problems were related to "removing patient duplication" and 33% (n = 38) were related to "registration of patient identification information". User agreement with the problems was high (CI 95% = 0.9 (0.96, 0.98)).

System problems often originate from user ignorance about what to do at each stage of using the system. Also, half of the system problems concern a mismatch between what users want to do and the system controls, or a lack of understanding about what the system does at different stages. Therefore, to avoid user confusion, designers should use clues and guides on the screen for users, design controls consistent with the user model of thinking, and provide appropriate feedback after each user action to help users understand what the system is doing. The high agreement of users with the problems showed that in the absence of users system designers can use CW to identify the problems that users face in the real environment.