Qualitative Survey: Types, Interview Guide and Analysis

Try a quick test. Every qualitative survey starts with the same choice: do you ask “How satisfied are you with the course?” or “Tell me how your last seminar actually went”? The first question hands you a number, the second one hands you reasons.

A qualitative survey is an open, barely standardized form of data collection: a small number of people describe a topic in their own words, so researchers can work out how those people interpret it and what drives their behavior. What makes the result sound is not the volume of answers but their depth and a careful analysis. By the end you will know which type fits your question, how many interviews are realistic and what your IRB will want to see before you start.

📌 Key points at a glance

• A qualitative survey means few people, open questions, own words.
• An interview guide fixes the topics and their order.
• Guest, Bunce and Johnson (2006) reached saturation after twelve interviews.
• Interview research often falls under an IRB exemption category.
• Qualitative analysis means building categories, not collecting quotes.

What is a qualitative survey?

A qualitative survey is a form of data collection in which a small number of selected people speak openly about a topic, so that their own wording reveals how they interpret it. There are no fixed answer options to choose from.

Asking becomes the method of choice whenever something cannot be observed and is only accessible through language. That carries a caveat worth stating plainly: people misremember, get things wrong and judge themselves too kindly. A subjective account is therefore not the same as an objective fact, which is why the analysis has to stay close to what was actually said.

The word “qualitative” describes the form of the data, not its worth. A qualitative survey is not the superior version of a survey, it is a different method with a different goal. If you need countable results, the quantitative survey is the right place to look.

Qualitative describes the form of the data, not its quality.

Which types of qualitative survey are there?

Qualitative surveys differ by their degree of standardization, meaning how tightly the course of the conversation is fixed in advance. Semi-standardized and non-standardized forms belong here; a fully standardized survey is already quantitative research.

The degree of standardization matters more than whether you meet in person, talk over video or use the phone. The channel changes the atmosphere, the degree of standardization changes the data.

Semi-standardized: the semi-structured and expert interview

In a semi-structured interview the topics and their order are set before you start. That takes you faster to the points your research question is about and makes several interviews comparable. It also costs something that is rarely named: the participant cannot set their own frame of relevance or develop their own narrative logic. When a specialist is asked about their own field, the same format is called an expert interview.

Non-standardized: the narrative interview and the focus group

In the non-standardized form only the topic is fixed. The participant speaks freely, you listen and deliberately hold back. What gets left out carries information too: what someone describes at length, what they treat as needing explanation and what they take for granted already says a great deal. A focus group follows the same logic, with the negotiation between participants added on top.

How do you build an interview guide?

An interview guide for a qualitative survey is not a list of questions to check off, it is a sequence of topics with invitations to talk. It keeps the conversation on subject without breaking it into bullet points.

Five steps are enough for a usable guide. The sequence comes from the practice of expert interviewing and transfers to almost any semi-structured interview.

1. Opening invitation. An open first question invites description instead of requesting an answer.
2. Immanent follow-ups. You ask for examples, descriptions and explicitly for counter-examples.
3. Exmanent follow-ups. You introduce topics that have not come up but belong to your research question.
4. Interpretation questions. You ask for the participant's own assessments, trade-offs and explanations.
5. Details about the person. Age, role or length of membership come at the end, never at the start.

Asking for a counter-example is the underrated part of that sequence. “Was there ever a situation where this did not work out?” surfaces in seconds the limitation that a stream of agreement would otherwise hide.

💡 Tip

Start the recording before the interview proper begins and let the consent be captured on tape. That way you lose neither the opening exchange nor the evidence that recording had been agreed.

How many people do you need for a qualitative survey?

A qualitative survey has no fixed minimum, it has a stopping rule: you keep interviewing until new conversations stop producing new themes. That point is called theoretical saturation, the moment when the category system stops changing.

There is still a solid orientation. Guest, Bunce and Johnson (2006) analyzed 60 in-depth interviews in stages in the journal Field Methods. Their codebook was largely complete and stable after twelve interviews, with basic patterns visible as early as six.

The rule of thumb people take from this is that twelve interviews are enough. That holds under one condition. Hagaman and Wutich (2017) revisited the study in the same journal: for a fairly homogeneous group at a single site, 16 interviews or fewer were sufficient, while themes meant to hold across several very different groups needed 20 to 40.

For a thesis that means six to twelve interviews are a realistic scope, as long as your participants resemble one another and your topic is narrow. What counts in the end is your department's guidance, since many programs set a minimum of their own.

Analyzing a qualitative survey: from recording to finding

Analyzing a qualitative survey means turning what was said into a category system that assigns every statement to a rule others can follow. Picking out the best quotes is not analysis, it is illustration.

The most widely used approach is qualitative content analysis, built on three basic forms: summary, explication and structuring. In practice the work runs through four steps.

1. Transcribe the recording word for word and anonymize names and places.
2. Read the material several times and build first categories directly from the text.
3. Code all interviews with that category system and sharpen the categories as you go.
4. Summarize the findings per category and support them with typical passages.

Step two decides the quality. Categories invented at the desk beforehand will reliably turn up in the material, because that is what you were looking for. Categories that grow out of the material surprise you, and that surprise is why you ran the interviews. The evaluation methods in empirical research put this into the wider picture.

Our reading tip

Philipp Mayring: Qualitative Inhaltsanalyse. Grundlagen und Techniken. 13th edition, Beltz 2022. The German-language standard work on the three basic forms, with process models and interpretation rules across 148 pages.

Benefits and limits of a qualitative survey

The main benefit of a qualitative survey is that answers nobody anticipated are allowed to appear. A questionnaire with fixed options cannot do that.

The limit sits in exactly the same place. Because every conversation runs differently, the results cannot be added up or transferred to a larger group.

What a qualitative survey delivers

• Unknown reasons and interpretations finally get spoken aloud.
• Misunderstandings can be cleared up on the spot.
• A handful of people is enough for solid first insights.
• Facial expression, hesitation and emphasis add further clues.

What you accept in return

• Analysis takes far longer than the conversation itself.
• Findings apply only to the people you interviewed.
• Your own interpretation enters every step of the analysis.
• Scheduling, recording and transcription eat a lot of time.

The last point is routinely underestimated. Transcribing a one-hour interview takes a multiple of the interview itself, and those hours fall due before the actual analysis has even started.

Common mistakes in qualitative surveys

Four mistakes show up again and again in theses and small practice studies. Three happen during the conversation, one happens earlier while recruiting participants.

All four share the same root: your own expectation turns into a specification instead of staying the thing under examination.

Mistake 1: leading questions in the guide

“Don't you think the dining hall has gotten too expensive?” already contains the answer. Questions like that produce agreement that says nothing about the participant and everything about the expectation built into the question. The test is simple: if a question points in a direction or can be settled with a yes, rewrite it. The article on open questions shows what good open wording looks like.

Mistake 2: trying to run the conversation yourself

Adding your own assessment to every answer means you get your own opinion back at the end. Restraint in a qualitative survey is therefore not a matter of style but of method: only then do the participant's priorities emerge instead of yours. Sitting through silences is part of it, however uncomfortable they feel.

Mistake 3: recruiting only from your own circle

People from your own seminar are quick to find, and that is precisely the problem. Anonymity cannot be promised to acquaintances, both sides are partial, and sensitive topics stay unspoken. On top of that comes the bias built into the route you used: a call for participants posted only on Instagram reaches people who are on Instagram. The recruitment route therefore belongs in your methods chapter.

Mistake 4: skipping the IRB and the consent form

Interview research with people usually needs an institutional review board determination before the first conversation, not after it. Under the revised Common Rule at 45 CFR 46.104, research using interviews with adults can fall into exemption category 2, provided the responses could not reasonably place participants at risk of criminal or civil liability or damage their finances, employability, education or reputation. Whether an exemption applies is decided by your IRB, not by you, and recordings that identify participants may still trigger limited review (as of August 2026). The article on data protection in surveys covers the rest. This article is not legal advice.

Conclusion

A qualitative survey earns its keep whenever you do not yet know which answers are possible. It gives you reasons rather than percentages, and it needs fewer people than most expect but far more time for the analysis. Plan for both from the start and six to twelve conversations will take you surprisingly far.

Where to go next

• Not sure whether your project is qualitative or quantitative? Qualitative and quantitative surveys compared
• Need the full course of a qualitative study? Qualitative research: process and methods
• Looking for the bigger picture? Empirical research: definition and guide

Want to collect open answers in writing as well?

An interview does not replace a survey tool and a tool does not replace an interview. For open questions to a larger group, empirio.ai, an online survey tool from Germany, gives you free-text fields and analyzes the answers together afterwards.

Create a survey online