SECTION CONTENTS

There are numerous methods available for data collection. The appropriate methods are chosen depending on the aims, design and resources of the research project.

Questionnaires are commonly used with survey designs. In Chapter 9, we examine a number of ways in which we can draw up and validate questionnaires. There are different types of questionnaires, ranging from highly structured, standardized scales to unstructured open-ended formats.

An interview (see Ch. 10) is, in a sense, a conversation between the interviewer and the person being interviewed. As they require the presence of an interviewer, this increases the cost and effort needed to obtain data. The presence of an interviewer may also influence the respondent’s answers. Qualitative research studies often employ in-depth interviewing techniques which are preferably carried out in the ‘natural’ settings (homes, hospital, etc.) in which the respondents are living or receiving treatment.

Observational methods are also commonly used strategies for data collection. They may range from highly structured observational protocols, indicating precisely which behaviours or clinical signs should be recorded, to unstructured records of the experiences of participant observers, as used in qualitative research.

Depending on how the data are recorded and analysed, interviews and observations may be used for both quantitative and qualitative research. However, the use of instrumentation to produce numerical data is most appropriate for quantitative research. A variety of standardized measurement instruments are now available for measuring biological and psychological functions (see Ch. 10).

Whatever data collection strategy is being used, we must ensure that it is reliable (replicable) and valid (accurate). Otherwise, as discussed in Chapter 12, the measurement error due to unreliable and invalid data collection strategies may prevent the researchers from achieving their goals.