KIIs are semi-structured interviews with people who hold relevant knowledge, experience or institutional perspective. They are strongest when informants are selected for what they can credibly know.
What makes someone a key informant?
A key informant is not simply a senior person. The individual should have knowledge, experience, access or perspective that is relevant to the research question. Depending on the study, this may include policymakers, programme managers, service providers, community leaders, distributors, industry experts, regulators or specialist practitioners.
The selection logic should be explicit: what information can this person credibly contribute that another source cannot?
When KIIs are particularly useful
KIIs are valuable for understanding systems, institutions, implementation decisions, market structures, policy environments and expert judgement. They are often used in evaluations, political economy analysis, feasibility studies, health systems research, market entry and programme design.
They can also help interpret quantitative findings. If survey results show unusually low service uptake in one location, KIIs with providers, managers and local stakeholders may identify supply, policy or implementation constraints.
Build a purposive informant map
Sampling is generally purposive. Map stakeholder categories and the perspectives required, then recruit informants within each category. Include contrasting positions where relevant rather than interviewing only programme allies or the most accessible experts.
The number of interviews should be driven by the diversity of perspectives and the point at which additional interviews add limited new insight, not by a universal numerical rule.
Use a semi-structured guide
A KII guide should contain core questions aligned to the research objectives plus probes that allow the interviewer to follow relevant expertise. Avoid long survey-style batteries. Senior informants are more likely to provide useful evidence when questions are focused and the interviewer can engage intelligently with their answers.
Questions should distinguish facts, perceptions and recommendations. “What is the policy?” is different from “How well is the policy implemented?” and different again from “What would you change?”
Interviewing skill matters
KII interviewers need subject familiarity, active listening and the confidence to probe respectfully. They should ask for examples, mechanisms and evidence without turning the conversation into an argument. For high-level stakeholders, strong preparation signals credibility and helps use limited time well.
Consent, confidentiality and attribution should be agreed. Some informants may speak more openly if findings are reported by stakeholder category rather than by name.
Analyse KIIs as evidence, not anecdotes
Create a coding framework linked to the research questions, compare themes across stakeholder groups and note areas of convergence and disagreement. Assess whether an informant is reporting direct knowledge, second-hand information or opinion.
KII findings become stronger when triangulated with documents, survey data, observations or other interviews. The purpose is not to count how many experts said the same thing; it is to understand the structure of informed evidence and what it means for the decision.
Select informants for knowledge, not convenience
The strength of a KII sample depends on whether participants genuinely hold the information or perspective needed for the research question. Informants may include policymakers, programme managers, service providers, community leaders, technical specialists, regulators, distributors, investors or other actors with relevant knowledge. Selection should be purposive and transparent.
Researchers can map stakeholder categories and identify the type of insight expected from each. Recruiting only the easiest or most senior people can create blind spots if operational or community-level perspectives are missing. The aim is coverage of relevant viewpoints, not statistical representation.
Prepare an interview guide that allows depth
A KII guide should be structured around a limited number of themes and decision questions. Open questions invite the informant to explain processes, incentives, constraints and examples in their own terms.
Probes can then test contradictions, request evidence or explore differences across contexts. The interviewer should know which questions are essential and which can be adapted to the informant's role. This is particularly important when interviewing diverse stakeholder groups: a regulator and a frontline provider should not receive an identical script if they hold different types of knowledge.
Manage hierarchy, confidentiality and sensitive topics
Key informants may speak about institutions, colleagues, political processes, commercial relationships or programme failures. They need a clear explanation of how their information will be used and whether quotations will be attributed. In some studies, anonymous reporting encourages candour; in others, role attribution is necessary for interpretation.
Researchers should avoid promising confidentiality that the reporting format cannot protect. Interviewers also need to manage hierarchy carefully, especially when participants are senior officials or powerful stakeholders. Respectful interviewing does not require accepting unsupported claims without probing.
Verify claims through triangulation
KIIs often produce expert interpretation rather than directly observable fact. A participant may describe a policy as effective, a market as growing or a programme as well implemented based on their own position.
Analysts should compare these claims across informants and, where possible, against documents, survey data, administrative records or observation. Contradictory accounts are not necessarily a problem; they may reveal different incentives, experiences or definitions. The analysis should state where evidence converges, where it differs and what remains uncertain.
Analyse KIIs systematically
A strong KII report is not a sequence of interview summaries. Analysts can code transcripts or detailed notes against a thematic framework, compare stakeholder groups and identify mechanisms, areas of consensus and important exceptions.
Matrices are useful for examining how the same issue is described by policymakers, implementers and beneficiaries or by different markets. Quotations can illustrate findings but should not substitute for analysis. The final output should explain what the informants collectively suggest, how credible the evidence is and what the implications are for the research decision.
Know when KIIs are not enough
KIIs are powerful for expert knowledge and stakeholder perspectives, but they should not be asked to answer questions better suited to other methods. They cannot estimate how common a view is across a population, and senior informants may not accurately represent frontline or beneficiary experience. When the study needs prevalence, consumer behaviour or direct observation, surveys, FGDs, audits or administrative data may need to complement the interviews. Recognising these limits makes KIIs more useful because they are applied to the questions they can answer well.
How Surveysphere Africa can support
Surveysphere Africa conducts stakeholder mapping, KII recruitment, interviewing, transcription and thematic analysis for evaluation, market and social research across Africa.
