ABSTRACT
This chapter attempts to condense a body of information that could fill an entire course. It divides into two sections. It provides a survey of the different methods by which verbal data are collected and a discussion of the strengths and weaknesses of each. Section 'Collecting and Evaluating Numerical Data' examines methods that typically gather numerical data followed by a discussion on how these data are judged as reliable and valid. The procedures under this heading involve capturing data through visual observation. The use of human observers as data collectors is as old as research itself. The quality of the data coming from an interviewer is determined by the care taken to ensure that the same procedures are used for each interviewee. Verbal data cannot be taken simply at face value, as neither can numerical data. The other method for collecting numerical data is using some form of impersonal instrument that requires participants to supply data to the researcher.
