In qualitative research, the core difference between a questionnaire and an interview lies primarily in the level of interaction, flexibility, and the depth and nature of data they yield. While both are tools for collecting information, an interview offers a much richer, dynamic, and in-depth understanding compared to a questionnaire.
Key Differences Between Questionnaires and Interviews
When conducting qualitative research, the choice between using questionnaires and interviews significantly impacts the type of data you can collect and the insights you can gain. Here's a breakdown of the key distinctions:
| Feature | Questionnaire (in Qualitative Context) | Interview (Qualitative) |
|---|---|---|
| Structure | Typically uses open-ended questions, but structure is fixed once designed. | Can be structured, semi-structured, or unstructured, allowing flexibility during the process. |
| Interaction | Minimal or no direct interaction with the respondent during completion. | Direct, real-time interaction between interviewer and respondent. |
| Depth of Data | Provides responses to specific questions but may lack context and nuance. | Allows for probing, follow-up questions, and capturing context and emotions. |
| Flexibility | Rigid; cannot adapt questions based on respondent's answers. | Highly flexible; questions can be rephrased, added, or removed based on the flow of conversation. |
| Context | Limited ability to capture the context surrounding responses. | Excellent for understanding the context, motivations, and perspectives behind responses. |
| Understanding "Why" | Less valid for understanding why something has occurred as it doesn't allow the respondent freedom to express thoughts in context (as highlighted by the reference). | More valid for understanding why something has occurred because respondents can express things in context and elaborate freely. |
| Logistics | Can be administered to many people simultaneously; generally lower cost and time per respondent. | Administered individually or in small groups (focus groups); higher cost and time per respondent. |
Why the Difference Matters in Qualitative Research
Qualitative research aims to explore experiences, perspectives, motivations, and meanings in depth. This is where the distinction between questionnaires and interviews becomes crucial:
- Capturing Nuance and Context: Interviews allow researchers to delve deeper into a respondent's answer. If a respondent gives a surprising or interesting answer, the interviewer can ask "Could you tell me more about that?" or "What led you to feel that way?". This dynamic interaction is impossible with a static questionnaire.
- Understanding the "Why": As the reference points out, a questionnaire will provide less valid responses than in-depth interviews or focus groups when you want to identify why something has occurred. This is because interviews and focus groups provide respondents with the freedom to express themselves in context, sharing insights the researcher may not have anticipated. Questionnaires, even with open-ended questions, constrain responses within the framework set by the researcher.
- Building Rapport: Interviews allow the interviewer to build rapport with the respondent, potentially leading to more honest and detailed responses.
Examples in Qualitative Research
- Questionnaire Example: Asking participants to write down their thoughts on a product feature using an online form with a large text box for each question. While open-ended, follow-up clarification isn't possible.
- Interview Example: Sitting down with a participant to discuss their experience using a product, asking open-ended questions, and then probing their initial answers to understand their specific pain points, feelings, and suggestions for improvement.
In essence, while questionnaires can gather some qualitative data (like open-ended text responses), interviews are the cornerstone of deep, exploratory qualitative research, enabling rich data collection and a true understanding of complex phenomena from the participant's perspective.
