Individual interviews

Interviews are a commonly used technique for data collection in qualitative research and can be described as a ‘construction site of knowledge where two individuals discuss a theme of mutual interest’. Interviews can be categorised into four types: the informal, conversational interview; the guided interview or topic approach; the standard open-ended interview; and the co-constructed dialogue interview. The four types vary in the degree to which they are structured, with one end of the continuum being unstructured, in-depth interviews where the researcher introduces a topic and then gives the interviewee the freedom to talk, with only occasional prompts and probes. This type of interview allows participants’ experiences, meanings, values and priorities to emerge with minimal interference on the part of the researcher, but it may be less useful for answering specific research questions. At the other end of the continuum, structured interviews comprising pre-defined questions are administered in a pre-set order.

Semi-structured interviews seek to obtain descriptions of the life of the interviewee with respect to interpreting the meaning of the phenomenon being described. They consist of a sequence of themes to be covered, as well as some suggested questions, with an understanding that changes to the sequence and form of questions are possible in order to follow up the specific answers given and the stories told by the participants.

Preparation for the interview stage usually involves a script called an interview guide, which structures the course of the interview more or less tightly. In a semi-structured interview the guide will include an outline of topics to be covered with suggested questions. Depending on the particular study, the sequence of the questions will be pre-determined and binding, or it can depend on the judgement and tact of the interviewer, who can follow up the interviewee’s answers and any new directions that open up.

The interview questions must be brief and simple. Different types of questions may be used. To allow for an easy start and to build rapport, introductory questions such as ‘Can you tell me about…?’ or ‘Could you describe in detail…?’ can be used, followed by questions to which the participants’ answers are extended through a curious, persistent and critical attitude on the part of the interviewer. This can be done through direct questioning of what has just been said or by a mere nod or ‘mm’. The interviewer can use probing questions such as ‘Could you say something more about…?’ or ‘Can you give a more detailed description?’ to pursue the answers without stating what dimensions are to be taken into account. The interviewer may also follow up with more operationalising questions, such as ‘What did you actually do?’ or ‘How did you react?’ The interviewer can introduce topics directly, preferably in the later part of the interview. Furthermore, interpretive questions can take the form of rephrasing the question or clarification.

Depending on the participants, some interviews need more careful consideration. For example, when interviewing people from a different culture, specific factors such as asking questions as a means of obtaining information, replying directly, referring to taboo matters, making eye contact when speaking or sending a man to interview a woman and vice versa need to be thought through in detail. Difficulties in recognising disparities in language use, gestures and cultural norms may also arise within the researcher’s own culture when interviewing across gender, generation, social class or religion. Although differences between subcultures may not be as pronounced as those between different cultures, if the researcher makes the implicit assumption that everyone belongs to a common culture, intercultural variations may be harder to detect.

When interviewing children, it is important to use age-appropriate questions and to be aware of several difficulties of interviews with adults that may be aggravated, such as the interviewer asking long and complex questions or posing more than one question at a time. In some instances, it may help to interview children while they are carrying out some other task such as drawing, reading a story, or watching TV or a video. See Box 10.1 for an example of a study using interviews.

Focus groups produce qualitative data that provide insights into participants’ attitudes, perceptions and opinions. These results are solicited through open-ended questions, to which respondents are able to choose the manner in which they respond, and from observations of those respondents in a group discussion. The discussions are audio-taped and transcribed. Careful and systematic analysis of the discussions provides clues and insights into how a product, service or opportunity is perceived. The researcher derives understanding based on the discussion as opposed to testing or confirming a pre-conceived hypothesis or theory. See Box 10.2 for an overview of the strengths and weaknesses of group discussions and Box 10.3 for an example of a study using group discussions.

The analysis of laddering data involves coding the attributes, consequences and values by a standard content analysis procedure. The summary table constructed represents the number of connections between the elements. From this the dominant connections can be selected and graphically represented in a tree diagram, called a hierarchical value map. Interpretation of this type of qualitative, in-depth information permits an understanding of a consumer’s underlying motivations with respect to a given product class. Each unique pathway from attribute to value represents an opportunity to understand the values driving food-choice decisions. See Box 10.4 for an example of attributes, consequences and values generated in a laddering study and Box 10.5 for a further example of this kind of research.

As opposed to self-reported behaviour, observational techniques allow behaviour to be observed directly. The data obtained is very rich because it includes non-verbal and physical behaviour. Measures of what, when, where and how much is being selected, purchased, prepared, cooked, shared or eaten can be collected by observers by photographing or filming behaviour. Data can be collected in unobtrusive naturalistic or controlled settings, such as observation labs where participants shop, cook or eat in a controlled environment that uses cameras and/or sensors to record behaviour. See Box 10.6 for the strengths and weaknesses of behavioural observations and Box 10.7 for an example of a mixed-methods study that included behavioural observation.