Interviews

Interviews are conversations between an investigator (interviewer) and a respondent (‘interviewees’, ‘informants’ or ‘sources’) in which questions are asked in order to obtain information.

Interviews seek to collect data and narrative information in order to better understand the respondent’s unique perspectives, opinions, and world-views. Interviewing is a fundamental methodology for both quantitative and qualitative social research and evaluation.

For Interviews with Individuals see:

A convergent interview is a type of interview intended to explore issues widely through a combination of unstructured interviews and a maximum diversity sample.

Key informant interviews involve interviewing people who have particularly informed perspectives on an aspect of the program being evaluated.

An in-depth interview is a type of interview with an individual that aims to collect detailed information beyond initial and surface-level answers.

For Interviews with Groups see:

A focus group is a type of group interview designed to explore peoples attitudes.

Types of interviews

There are many different types of interview approaches and techniques, Generally speaking, all interviews fall into one of three categories: structured, semi-structured, and depth/unstructured interviews.

In practice, these three approaches are routinely combined. Qualitative exploratory interviewing, for instance, can prove a good compliment to more structured interviewing using closed questions later in an evaluation.

A large number of more specific interviewing techniques fall under this broad taxonomy; including telephone interviews, computer-assisted interviewing, elite interviewing, life histories, household surveys and Key Informant Interviews which are interviews with people who have particularly informed perspectives on the project. (Group interviews, including focus groups, and survey research require sufficiently specialized methodological approaches as to be considered separate from general interview methodology, although many of the fundamentals overlap.)

Whatever approach the investigator selects, the interviewing processes itself follows several general stages:

Conducting the interview itself is as much ‘art’ as ‘science’, and requires practice. That said, the following steps provide a useful guide:

Keep in mind that specific interview techniques will require important variations of this approach – a telephone interview is conducted very differently than a one-to-one interview, as is a focus group. See relevant options entries for more on each.

Examples

This following example of a semi-structured interview guide was prepared for the World Health Organization's (WHO) training package on substance use, sexual and reproductive health as part of the M&E component of a street children project.

Interview guide with fields for details of the interviewer, interviewee, place and date at the top followed a set of interview questionsquestions

Advice for choosing this method

In general, interviews have the following strengths:

And the following weaknesses:

Advice for using this method

Interviewing is a unique and somewhat intuitive skill which requires practice. The following are a few, but by no means all, guidance on how to ask good questions.

On question design:

Resources

This paper from the United States General Accounting Office (GAO) explains structured interview techniques for GAO evaluators and how they should be incorporated when appropriate.

This short guide defines in-depth interviews, explains their advantages and disadvantages and the steps involved in their application.

This webpage outlines the circumstances in which qualitative interview techniques are best applied for the purpose of evaluation.