Evaluating the Usefulness and the Ease of Use of a Web-based Inspection Data Collection Tool

This paper contributes a valid and reliable measurement instrument in the form of a questionnaire to determine, from a user’s perspective, the usefulness and ease of use of a Web-based Inspection Process Support tool (WIPS) that we developed for inspection data collection. The questionnaire is built upon the work of Fred Davis on perceived usefulness, ease of use, and usage of information technology. To validate the questionnaire and its underlying model as well as to evaluate WIPS, we performed a controlled experiment with computer science students as subjects. The subjects performed inspection of a code module and used WIPS for collecting defect and effort data. Once they had completed the code inspection, they filled out the usefulness and ease of use questionnaire. Our experimental results provide empirical evidence that the questionnaire is a reliable measurement instrument (cronbach alpha: 0.84 for usefulness; 0.82 for ease of use). Factor analysis revealed that the questionnaire items discriminate between two different concepts: usefulness and ease of use. Since WIPS received high ratings for both concepts, we can conclude that the subjects consider WIPS useful and easy to use. These results, together with the fact that usefulness was significantly correlated to selfpredicted future usage, imply that our subjects preferred WIPS over paper-based forms for inspection data collection. We are aware that a single experiment does not provide conclusive evidence. Hence, we consider our results as a baseline against which other researchers can compare their results when utilizing the presented questionnaire. However, its use is not limited to inspection tools, but applies to the usefulness/ ease of use evaluation of tools and techniques in general. To demonstrate this, we present preliminary results of a controlled experiment we are currently performing with professional software developers in an industrial setting to evaluate different inspection techniques.