Key informant interviews

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

Key informant interviews are "qualitative, in-depth interviews of 15 to 35 people selected for their first-hand knowledge about a topic of interest. The interviews are loosely structured, relying on a list of issues to be discussed. Key informant interviews resemble a conversation among acquaintances, allowing a free flow of ideas and information. Interviewers frame questions spontaneously, probe for information and take notes, which are elaborated on later" (USAID 1996).

USAID (1996) lists a number of situations in which key informant interviews are useful:

  1. When decision-making can be achieved through qualitative and descriptive information.
  2. When it is important to gain an understanding of the perspectives, behaviour and motivations of customers and partners of an activity or project in order to explain the shortcomings and successes of an activity.
  3. When generating recommendations is the key purpose.
  4. In order to interpret quantitative data by interviewing key informants about the how and why of the quantitative findings.
  5. In order to help frame the issues that are relevant before designing a quantitative study.

Advantages to this method include:

  • They are an affordable way to gain a big picture idea of a situation.

  • The information gathered comes from people who have relevant knowledge and insight.

  • They allow for new and unanticipated issues and ideas to emerge.

Limitations to this method include:

  • There is a potential for the interviewer to unwittingly influence the responses given by informants.

  • There is a potential bias if informants are not selected with care.

  • Systematic analysis of a large amount of qualitative data can be time-consuming.

  • The validity of the data can sometimes be difficult to prove.

Advice for using this method

  • When formulating study questions, limit the amount to five or fewer.

  • The interview should allow for free discussion by informants however, interviewers should be aware of what questions to ask and topics that should be covered. 

  • When preparing a guide for interview topics, items are usually limited to 12 items so as to allow for in-depth discussion. It is sometimes useful to prepare different guides for different groups of informants.

  • When selecting key informants, it is often a good idea to start with a smaller amount as initially unplanned informants are often added. The total number generally is no more than 35.

  • In selecting key informants, make sure to include a wide range of perspectives and points of view, including selecting from different groups of key stakeholders.

See Interviews for more general advice on interviewing.


Pact, Inc. (2014), Field Guide for Evaluation: How to Develop an Effective Terms of Reference. Washington.

USAID Center for Development Information and Evaluation (1996) Conducting Key Informant Interviews  Performance Monitoring & Evaluation TIPS. Washington DC, USAID. Retrieved from via USAID

'Key informant interviews' is referenced in: