Interviews provide a qualitative method of gathering evidence, data or information. Responses are not usually expressed in numerical terms, as might be the case with questionnaires.
If you are planning to carry out interviews as part of a research project, the first things to consider are who you will interview, what kind of information you want to obtain, and the type of interview that will help you to do that.
- Unstructured interview. The interviewer uses at most an 'aide memoir' - notes to jog the memory - rather than a list of questions. The interview may be like a conversation, with the interviewer responding to the interviewee and letting them speak freely.
- Semi-structured interview. The interviewer has a list of questions or key points to be covered and works through them in a methodical manner. Similar questions are asked of each interviewee, although supplementary questions can be asked as appropriate. The interviewee can respond how they like and does not have to 'tick a box' with their answer.
- Structured interview. The interviewer asks the interviewee a series of specific questions, to which a fixed range of answers are possible ('ticking a box'). This is the typical form of interview used in social survey research, and can provide quantitative data, as in a questionnaire.
When you design your project you need to take into account how many people you need to interview to make the research valid or for 'population validity'. If you are investigating a narrow but deep subject you may not need to interview that many people. You may be interested in the opinions and experiences of experts or people with direct experience - a purposive rather than a random sample.
If you are interviewing a small number of people you must make sure that the sample is as appropriate as possible to your research.
Larger samples are normally employed in quantitative research using methods such as questionnaires.
Preparing an interview guide
When preparing an interview guide you need to keep in mind the following points.
- Make sure you introduce yourself and explain the aim of the interview. Also adhere to academic ethics by making sure the interviewee is fully aware of the purpose of the research
- Devise your questions so they help to answer your research question, and make sure all the questions are relevant
- Try and have a sequence to your questions or topics by grouping them in themes that follow a logical sequence
- That said, make sure that you can easily move back and forth between questions or topic areas, as your interviewee may naturally move on to another subject
- Make sure your questions are clear and easy to understand - only use technical or academic language if you are sure your interviewee will understand what you mean
- Do not ask leading questions. Make sure people are free to give their own, honest answers.
Kinds of question
Kvale (1996)* has identified nine types of question asked in qualitative interviews. Keep these in mind when you are composing your interview guide.
- Introducing questions: 'Why did you...?' or 'Can you tell me about...?' Through these questions you introduce the topic.
- Follow up questions: Through these you can elaborate on their initial answer. Questions may include: 'What did you mean...?' or 'Can you give more detail...?'
- Probing questions: You can employ direct questioning to follow up what has been said and to get more detail. 'Do you have any examples?' or 'Could you say more about...?'
- Specifying questions: Such as 'What happened when you said that?' or 'What did he say next?'
- Direct questions: Questions with a yes or no answer are direct questions. You might want to leave these questions until the end so you don't lead the interviewee to answer a certain way.
- Indirect questions: You can ask these to get the interviewee's true opinion.
- Structuring questions: These move the interview on to the next subject. For example, 'Moving on to...'
- Silence: Through pauses you can suggest to the interviewee that you want them to answer the question!
- Interpreting questions: 'Do you mean that...?' or 'Is it correct that...?'
Recording the interview
In both unstructured and semi-structured interviews a method of recording the responses is required. This can be by digital recording or note taking (with the informed consent of the interviewee). In either case the interview process is a flexible one, with the emphasis on the answers given by the interviewee.
You should make sure that your interviewees have agreed to be interviewed. If they agree to be interviewed but decline to be recorded you can still go ahead with the interview, although your note taking would focus on writing down key points.
Once you have completed your interviews you will have to transcribe your notes by copying what was said into a word-processed document. Modern digital recorders allow you to download a recording onto a computer and then slow it down to a useful speed. Transcribing can take a very long time - a ten-minute interview could take one hour or more to transcribe, depending on how quickly you can type, how fast the interviewee speaks and how clear the recording is.
If you only have a short time in which to complete a research project make sure you do not over-estimate the number of people you can interview and transcribe.
Once you have completed the interview, reflect on how it went. Was there anything you could have done better? Do you need to add any questions or topic areas? Is there anything you should have explained to the interviewees?
Once you have transcribed your interview(s) you may have a lot of data. How are you going to analyse it?
Some of it won't be useful, perhaps because the interviewee didn't keep to the subject, or gave background information which is not needed.
Of the relevant information, you could pick out key points and quotes to illustrate your points. You could also code the information - essentially you could turn a qualitative interview into quantitative data. You would do this by identifying passages of text and applying labels to them to show that they are an example of a theme. For example, if you asked 20 people how they travelled to work and one of the answers given was 'by car' this would be one thematic code. 'By bike' could be another, as could 'walking', etc.
You could perhaps code car as '1' and 'bike' as '2' etc., and then add and analyse the data in a spreadsheet, thus giving you the chance to generate charts and graphs to better illustrate your answers.
You could also use a qualitative research tool such as Nvivo, a program that helps you to classify your data using codes. Alternatively, if you had a small sample you could simply create a table on a piece of paper listing how many people said 'car' and how many said 'bike'.
* Kvale S. (1996) InterViews: An Introduction to Qualitative Research Interviews, Sage Publications, California