Each subject performed the given tasks by answering six questions on the NP design and six questions on the VP design.
All subjects answered the same questions.
Both of four groups answered the questions from Questionnaire A (Q-A) and Questionnaire B (Q-B) according to the Diagram No.
as shown in Table I. The Questionnaire A is designed to ask questions related to System-A and Questionnaire B is designed to ask the questions related to System-B.
The details of these questionnaires are illustrated in Appendix B.
The questions were designed in such a way that each class diagram contained enough information to answer the questions.
Typically, questions involved three or four classes and ask specific questions to the subjects with each design alternatives.