Self-Report Instruments and Methods

Publisher Summary This chapter discusses the possible problems in using survey methods in traffic research. For that it concentrates on questionnaires as self-reports. Most of the examples are from driver behaviour questionnaire (DBQ) literature because the DBQ is one of the most widely used instruments for measuring driver behaviors and, thus, provides good demonstration material. Self-reports include a great variety of different methods, including questionnaires and inventories, interviews, focus groups, and driving diaries. Common features in all these diverse self-report measures are that participants are aware that they are participating in a study; they are asked to actively reply to more or less structured questions; and their responses are taken as “face valid”—that is, answers are scored and analyzed based on the responses and not, for example, according to response time or other behavioral or physiological measurement. Self-report methodology has been used for a wide variety of research, including attitudes, opinions, beliefs, emotions, cognitive processes, behaviors, and basically any aspect of driving. Although self-reports can offer a rich source of information, they also have some serious shortcomings and limitation that have to be taken into account. Review of studies using self-report methodology shows that traffic researchers pay far too little attention to the psychometric characteristics and validity of the tests.