Interviews are a key research tool. Interviews differ from surveys in that they are conducted verbally in a one-to-one setting and include open-ended questions. Therefore, interviews are qualitative research. That is, the responses provide non-numerical data. There are three main types of research interviews: structured, semi-structured and unstructured. The types of interviews are defined by how much scope the interviewer has to deviate from the pre-prepared questionnaire (or if there is a questionnaire at all).
Interviews can provide extensive information about a topic, which may even go beyond the interviewer’s knowledge of the topic. They can be particularly helpful in market research to gather attitudinal insights. For example, this could be customer satisfaction or gauging the demand for a new product or service.
So, how can you utilise this powerful market research tool? In this article, we will go into detail about each type of interview, their advantages and disadvantages and how SurveyMonkey’s questionnaires and survey templates can help you conduct more effective interviews.
A structured interview, or standardised interview, asks the same questions in the same way to each participant. The questionnaire is fixed, and the interviewer must proceed with it in the predefined order. They cannot prompt the participant to give a more detailed answer or intuitively follow up on any statements made.
Structured interviews contain mostly closed-ended questions, such as, ‘Would you recommend our product?’ or ‘Do you think our service is excellent, good, average or poor?’ However, it is common for open-ended questions to be added at the end of the interview, such as, ‘Do you have anything to add?’
As the majority of the questions are closed questions where the participant selects an answer, whether it be yes, no or another predefined response, structured interviews are less time-consuming to analyse. However, the data gathered is not as in-depth or nuanced as with other types of research interviews.
A semi-structured interview, similar to a structured interview, is planned in advance with a predefined questionnaire. However, instead of asking mostly closed questions, a semi-structured interview comprises entirely open-ended questions. The interviewer can also go off-script in obtaining more detailed information, such as prompting the participant to expand on an answer or a specific part of their answer. This is an example of a semi-structured interview:
Interviewer: ‘How could we improve our customer service?’
Participant: ‘I would like to see more information on new product features – I know there’s the user manual, but no-one has time for that!’
Interviewer: ‘What kind of educational material would help you most?’
Given the open-ended questions, conducting semi-structured interviews and analysing the results is more time consuming. The responses cannot be directly compared but rather have to undergo a thematic analysis to see if common themes emerge. Yet, insights from this type of interview can be highly informative and comprehensive and provide more qualitative data.
An unstructured interview, or in-depth interview, is the least structured of the three types of research interviews. They are used to get a rich picture of only a few, perhaps even just one or two, topics. There is an extremely limited questionnaire or no questionnaire at all. Rather, subsequent questions are derived from the participant’s answers.
This type of interview is best utilised when there is a clear and specific research question to be explored in great detail or when dealing with subjective human experiences. They may be useful in market research, for example, when testing a new product or if insights are needed on, for instance, the customer journey or user experience.
Unstructured interviews are the most time-consuming to conduct and analyse. With this type of interview, quantifying the data to make a comparison or statistical analysis is not the end goal. The aim of the interviewer is to get the full picture of a topic from each participant.
| Type of interview | Advantages | Disadvantages |
| Structured | Least resource heavy Many topics can be covered Most easily analysed | Interview least in-depth Limited insights on topics Narrow data |
| Semi-structured | Moderately resource heavy Many topics can be covered More comprehensive answers Interviewer can clarify/follow-up on statements | Interview moderately in-depth Mid-level insights on topics Data harder to analyse Interviewer bias |
| Unstructured | Most in-depth interview Rich picture of a few topics | Most in-depth interview Rich picture of a few topics Most resource heavy Data most difficult to analyse and may not be generalisable |
Interviews are a valuable market research tool, especially for gaining attitudinal or experiential insights. The three types of interview are structured, semi-structured and unstructured. They differ in their format and how predefined the questions to be asked are. All can be useful, but semi-structured interviews are the most popular given they are moderately resource heavy but yield expansive results.
Want to make the most of interviews in your market research? SurveyMonkey can help. Our bank of questionnaires and survey templates will help you conduct effective interviews more efficiently, cutting down on preparation time and guiding you on what questions will generate the best insights for your research interests.
An interview is conducted verbally, in a one-to-one format between an interviewer and participant. The interviewer asks either closed- or open-ended questions to gather information on topics related to the research interest.
The three types of research interviews are structured, semi-structured and unstructured.
A structured interview is when all participants are asked the same questions in the same way. The questions are mostly closed questions prepared in advance and administered in a predefined order.
A semi-structured interview is when a series of predefined open-ended questions are asked to participants, but the interviewer has some leeway to order them as they wish or give prompts to clarify and expand answers.
An unstructured interview is when there are limited or no predefined questions, but rather the aim of the interviewer is to gain a rich picture of the one or two topics of the research interest. The interviewer uses previous responses within the interview to frame their questions.