I am looking for references to look for the criteria of experts groups before conducting pilot testing. The experts i believe will receive the questionnaires to review before the real study being executed.
All Transportation Experts who have worked for public transport should be able to help you in reviewing the questionaite that will be prepared in terms of the performance and service quality. There is no directory for such workers, but authors of the selected research papers should be able to do a good job. Even if you take all known Transportation Experts, you can select those responses only, which are found to be logical answers, and others can be kept aside.