Asking questions person to person is an important feature of social life – it is something we all do all the time. Interviews in evaluation and research are a focused and systematic way of asking more or less structured questions of people who can provide the information needed. The focused and systematic approach is assisted by the use of an interview schedule, which is frequently used to guide an interview towards the data of interest. Interview schedules can range from a series of very precise, fixed answer questions to very broad general questions where an interview is conducted much as an ordinary conversation, but with the difference that one participant to the dialogue (the interviewer) is trying to obtain information and understanding from the other about some very specific issues.

The former type of interview, with closed fixed questions, is essentially a spoken questionnaire, and is used where a written questionnaire would not be feasible. These are generally when the respondents are difficult-to-reach groups (unlikely in probation, market research is the classic example), groups which have difficulty reading written English (more common in probation evaluation), and as a means of improving response rates. Interviews are much more expensive than questionnaires because of the time required of the interviewer, but response rates are generally very much higher with an interview than with a postal questionnaire. A useful alternative to the face-to-face interview is the telephone interview, which also has generally high response rates but takes less interviewer time.

The qualitative, open interview is guided by a ‘focused interview schedule’, which is a list of the broad questions to be asked and lists of points which the evaluator wants to be covered in the response. Qualitative interviewing is a skilled task requiring an interviewer who understands the purpose of the interviews and the sorts of issues that are of interest to the evaluator. This knowledge will enable the interviewer to engage in a meaningful dialogue with the respondent, following and probing relevant issues raised in the response but not identified on the interview schedule.

Interviews are time consuming in both collection and analysis, so it is important to devise a schedule which obtains the required information as quickly and as reliably as possible. It is critical that sufficient time and attention is given to preparing and piloting interview schedules.

Repertory grids are a useful technique when a detailed understanding of someone’s values and attitudes is important. The technique elicits from the respondent the ‘constructs’ (dimensions of attitude) that are relevant to them, and then goes on to allow quantification of those attitudes. The strength of this technique is that it can be used to gain an understanding of a respondent’s ways of thinking about a particular issue, for instance particular people. One way of using the technique is to ask the respondent to use their own constructs and then quantify those constructs in relation to several people, such as a person who is liked, a person who is disliked, the respondent in a particular environment (such as in a groupwork session), or indeed their supervising officer. For example, this technique has been used successfully to elicit offender and community service staff views of different sorts of community service task. Repertory grid work is well established within probation evaluation, and is best used in a qualitative way with small numbers because of the complexities of the analysis. A useful text, which provides more guidance on the technique and illustrates the range of uses relevant to probation practice, can be found in Maitland (1990).

Sentence completion and indirect questioning are both useful techniques. Another technique, which can produce interesting results, is the personalisation of objects, for instance ‘If this building were a person what would it say/think?’. An alternative to this theme is the question such as ‘If your probation officer were an animal, what would s/he be?’ It is important with these techniques to follow up with the probe ‘Why do you say that?’ to obtain the understanding required.

The life history approach is a whole interview rather than a specific question technique, and is very valuable for gaining insights into a person’s background. It is likely that a series of interviews would be required for this exercise, rather than just one. For this reason it is a particularly valuable technique when used with a case study evaluation design. In this design a very small number of cases (sometimes a single case) are chosen very specifically because they display certain characteristics. For instance, they may have been an outstanding success following a particular intervention and the evaluator wants to learn more from this experience. Although called a ‘life history’, it is not essential to cover the whole of the life of the respondent, but to focus on the issues related to a specific relevant period of time in the life of the individual.