Interview techniques in psychology are a matter of judgement, but perhaps there are some common sense rules which emerge from good practice. I outline some of them below, but please take them as suggestions rather than hard-and-fast rules.
When planning your approach, it helps to divide your thinking into two aspects:
1. etiquette, and
Etiquette is all about the social niceties: how can you make the client feel at home; how can you begin the interview appropriately; how can you politely lead to the meat of the issue; how can you bring things to an end politely; and how can you leave the participant feeling all right about you and the world?
I suggest you plan your interview in the following 8 stages:
1. Pre-interview communication and arranging: make sure you make a clear arrangement to meet at a location that is comfortable and undisturbed. Greet the participant at the arranged time, and lead them to the appointed place, making sure they are comfortable.
2. Basic information: remind the participant why you are meeting, how long the interview will be, and what will happen.
3. Consent: ask the participant to sign any necessary consents, if they haven't already done so.
4. Demographic information: gather any background information you need for the research early on, so that the participant is not disturbed at the end, when they may want to get away.
5. Explain that the interview is about to start: it is good courtesy to be clear as to exactly when you are starting recording, and to confirm with the participant that they are comfortable.
6. Early interview: it is good etiquette to begin with a few easygoing questions, to allow the participant to acclimatise themselves to the situation.
7. Mid-interview: it is good to remain sensitive to the participant comfort by checking from time to time that they are happy with the way things are going.
8. End-interview: it is good to introduce the participant to the fact that you are coming to a close, and check whether there is anything else they would like to say. It helps them to feel in control and at ease.
9. Debriefing: it is good to offer the participant a final check of their comfort, and give them a summary of what the whole interview has been about; also to let them know whom to contact in the event of any issues arising.
10. Goodbye: a friendly goodbye leaves the participant with a good feeling.
The above dealt with how to structure your interview. But during the interview, there are some definite techniques to bear in mind in terms of how you gather the information. These points are more to do with how you handle the conversation. The following are five key points I suggest you consider at all times. I have listed them as tensions, because all the time you will be asking yourself about the situation, and how you should be in the moment:
1. 'Leaning forward' versus 'sitting back': with a confident participant, you may be able to sit back and let them flow, only offering occasional encouragement. But with a less confident participant, you may want to consider helping them through more actively. Examples include nodding more vigorously, smiling more often, and saying 'that's interesting', or 'mm' more frequently.
2. 'Leading to' versus 'being led': if the participant seems to be straying from the subject, ask yourself if you can see a relevance to what they are saying. If you feel you are being led badly off-piste, then you can choose to lead the participant back to the subject of interest. You could say 'that's really interesting' in order to reduce any sense of rudeness, immediately followed by 'I wonder if I could ask you...' to get the interview back on track. If you are not sure where the interviewee is going, then it is good to ask for clarification, perhaps with a question like: 'do you think there's a connection between what you're saying and [insert the topic here]'. It may be that you have missed an important connection or relevance, and it's important to pick it up. There is no easy answer on this one, as you need to let the interviewee roam fairly free, but at the same time you have limited time to gather your information.
3. Divergent thinking versus convergent thinking: be clear in your mind whether you are asking the participant to free-associate, or come to a view. The former is divergent, the latter convergent. For example, one pattern might be to ask a convergent question: 'what do you think people should...?', followed by a more divergent question such as 'can you tell me more about that?' This 'C-D' pattern is useful for exploring the reasons and context for opinions, for instance. Another pattern might be to go 'D-C', in other words to ask a much more open question, and then focus in later. You could ask: 'could you talk to me about X in whatever way you like'; and then later, depending on what emerges, converge by asking: 'I notice you used the phrase Y; that sounds interesting; can you tell me more?' This 'D-C' pattern is useful for getting an idea of the overall territory, and then focusing in on interest points.
4. Body language versus words: You have an advantage over the reader of text: you are present with the interviewee. Pay attention to their tone, their body language, your sense of how they are responding. It will give you clues as to avenues of interest. You may choose to ask a question that draws attention to an incongruence; for example 'when you were talking about X, I noticed you made a face when you mentioned Y... I wondered what was going on for you?' That way, you can elicit information not available through words alone.
5. Your views versus the interviewee's views: This is a tension not often talked about, as we like to think we're impartial. But you have a view, and you need to remain reflectively aware how that might influence your behaviour in the interview. Are you only smiling when the participant says certain things? Are you only saying 'that's interesting' when the participant says what you would want them to say? Your aim is to gather information that may be unexpected, and it does not help to influence that process with expectation. However, on occasion you may want to be open about your surprise, if you feel it is congruent, such as saying 'Wow! I didn't see that coming - can you tell me more about what you mean?' As long as you remain curious, interested and friendly, and do not inhibit the participant's flow, a natural display of humanity can help them to feel that this is a relationship in which free information flow is comfortable and encouraged.
In summary, have a good structure within which you and the participant can work; and then, depending on the situation, manage your interventions with sensitivity, keeping in mind (a) what information you are interested in gathering, and (b) the client's behaviours and responses.
I hope this is helpful to some - it's really a digest of the main things I have found helpful when planning and conducting my own research interviews.
A FINAL ETHICAL NOTE
One final thing - all of the above is subject to the overriding concern of the wellbeing of all participants. If at any time the participant seems unduly uncomfortable, then it is in order, and desirable, to check how they are, and take any necessary action, before resuming.