Longitudinal Qualitative Research is a relatively recent development which has yet to be fully articulated as a coherent methodology (Neale & Flowerdew, 2003:189), although examples of this style of research can be traced back several decades. There are few books which deal with it in any depth (although see Saldana, 2003). In this essay I am going to; outline longitudinal qualitative research (QLR); address the main features of it; provide an outline of its strengths and weaknesses; describe its advantages over other forms of research styles; and provide an exemplar of a study which employed QLR research design. What is QLR?
QLR embodies a range of mainly in-depth interview-based studies which involve returning to interviewees to measure and explore changes which occur over time and the processes associated with these changes (see Holland et al 2004 for a full review). The approach is particularly useful if one is studying a process which has a notion of a ‘career’ of some sort or which involves a developmental process. For example, I study why people stop offending, which clearly involves understanding the processes by which an individual comes to realise the harm they are doing to both themselves and others, makes efforts to resist their engagement in crime, overcomes stigmas, builds relationships with non-offenders and so on. Similarly, studies of ageing or of other developmental processes (parenthood, changes in structural location such as from employee to retiree) are suitable for QLR. There is currently no definition – nor will there ever be I suspect - of how long studies should last, nor is there any guidance in the literature as to how long the time intervals 2 between interviews ought to be. It is clear that, depending on the subject matter at hand, these sorts of decisions will need to be left to researchers and guided by their preferences and the nature of their studies. A study of the emotional strains placed on a relationship during first-time pregnancies would, one would imagine, need to last the best part of a year. However, a study of decision making in relation to career choices could last years, if not decades. Nor is there any suggestion that QLR studies have to be predominantly interview-based. Although I exclude ethnographic studies from this review, since these are almost always longitudinal in nature in that most ethnographies involve at least twelve months of fieldwork, there are some studies (e.g. MacLeod 1997) which have embedded interviews in wider ethnographies and have retuned to subjects in order to complete a follow-up. I also exclude from this review those styles of qualitative interviewing which require repeated interviews for some other strategic purpose (e.g. psycho-analytic interviews, see Hollway & Jefferson, 2000). In essence, QLR studies often involve the following sorts of research design, although as Holland et al 2004:1 note, it is hard to draw precise boundaries around differing styles of QLR studies: • In-depth interviews repeated at roughly fixed time intervals with the same people led by the same research team; • Retracing respondents from an earlier study originally undertaken by a different research team; • A once off long term follow-up of the lives of a particular group or groups of people. 3
In this review I am going to focus on the first of these. I make this choice since a) this is where my expertise lies, b) the other research designs are more idiosyncratic and therefore harder to draw firm conclusions from or lessons about in a review of this length and c) some these research designs may become untenable under research ethics guidelines. For example, returning to respondents from an earlier study originally interviewed by a different team of researchers raises questions around who ‘owns’ the data and the right (within reason) for respondents to decide who conducts research into themselves and their lives. What Are the Strengths & Weakness of QLR?