Interviewing is a frequently used method in evaluation research with its suitability being entirely dependent on the particular research questions.  The method can be particularly helpful in collecting participants’ feelings, thoughts, experiences, beliefs and opinions about a topic in a one to one situation.  Interviews are among the most challenging and rewarding forms of qualitative research. They require a personal sensitivity and adaptability.

One of the most important aspects of any interview process is the interviewers themselves.  Interviewers need to be able to put interviewees at their ease and relate to a range of different people sensitively and respectfully.  They may also have to deal with difficult situations arising from discussion.  Interviewers need to be well briefed about the purpose of the research and may need further training about what to do in particular circumstances. 

Asking Questions

In interviewing, as with surveys and questionnaires, the design of your questions is key. Questions should be carefully planned and piloted before beginning the interview process. Please see the section on Asking Questions for more details.

Probes, follow-up questions, and clarifications

One of the benefits of interviews as a method is that it allows you to ask follow-up questions andprobemore deeply about your respondent’s thinking. “Could you tell me more about that?” is a wonderful, non-leading way to encourage a participant to provide more information. In addition, “what makes you say that?” is a way to elicit some of the thinking behind their statements (as long as you are careful to keep a neutral tone).

In addition, it is helpful to prepare an alternate way of asking questions ahead of time, in case a respondent doesn’t understand what you are asking and you need to explain it a different way. Planning this out instead of winging it can greatly reduce the chance of asking a leading or confusing question.

Think time

Many people are uncomfortable with silence, and are quick to assume that silence means that their question wasn’t understood and needs clarification. This is not always the case. When conducting an interview, make sure you give your respondents enough time to think and consider their answer. A good rule of thumb is to silently count to ten before clarifying, re-wording, or moving on to the next topic.

How long?

As a general rule, interviews should last between 30-90 minutes. However, the needs of your particular population should always be kept in mind, and you should recognise when people will need more or less time. One approach is to prioritise your list of questions, so you know which topics are most important to cover, and which topics could be covered if you have enough time.


Ethics have been discussed elsewhere in this toolkit, but it is important that all interviewers keep their participants’ well-being at the forefront of their mind. If a respondent is upset or shaken by the questions you are asking, stop the interview. Likewise, if you as an interviewer feel unsafe for any reason, stop the interview and leave. It is better to stop too early and come back later than to keep going and potentially lead yourself or another to harm.

Recording your interview

In the past, information from interviews was only recorded in note form. Today, however, high-quality digital recorders (both audio and visual) are relatively inexpensive, and are a popular method of recording interviews.  If you are using an audio or visual recording, it is vital to obtain informed consent ahead of time.  You must also think carefully about data protection, storage, and how the recordings will be used in the future. See the Ethics section for more details on this topic.  

Selected methods and techniques

There are three main formats that interviews may take and it is important to recognise and apply the most appropriate format for your research.

a)    Structured Interview (standardised approach). These are also discussed previously in the survey section.  Normally, structured interviews are carried out face-to-face or via telephone using a standard planned set of questions to obtain data that can be aggregated because identical questions have been asked of each participant. This is most useful when adopting a standardized approach to verify information is more important than exploration of understandings. 

b)    Semi-structured Interview (Interview guide approach). A semi-structured interview uses a planned set of questions, but is more flexible in approach, allowing new ideas to be brought up during the interview as a result of what the interviewee says. The format tends to be more conversational and the interviewer can use probes or ask follow up questions to get more in depth responses.

c)    Unstructured Interview (conversational approach). Normally, unstructured interviews are carried out face-to-face and are really about trying to get participants to open up and share their experience. This type of interview might still use some pre-planned prompts, but is more like a free flowing conversation and allows for the interviewee to influence the direction of the conversation.  This is most useful when you need to privilege discovery over verification.


  • Get full range and depth of information
  • Personal
  • Develops relationship with participant
  • Allows for participant flexibility      


  • Need a good and trained interviewer who is clear about the purpose of the research
  • Can be time-consuming (particularly transcription from audio or handwritten notes)
  • Can be hard to analyse and compare
  • Interviewer can bias participant’s response
  • Data reflects participants’ biases
  • Can be expensive



The types of interview approaches are varied, and you should carefully consider which is best for your project and the interviewer.

There is a wealth of material available on interviews and interview technique. For example, the UK Data Service provides a useful introduction to Interview Methods and covers a various types and methods.