ABSTRACT
Research is about more than empirical evidence, but evidence is at the heart of finding out more about the social and education world. One way of marshalling evidence on a topic, or to answer a research question, is to use the findings of others as published in the literature. This use of evidence at third hand is common – in the notorious literature review for a PhD, for example. I say ‘third hand’ because the analyst does not have access to the primary evidence, nor are they re-presenting an analysis of the data. They are presenting a summary of what a previous author presented about an analysis of data. Done well, with a clear focus, such a review of literature can be useful, at least in establishing what others think, how a topic is usually researched, and why the topic might be important to research further. Some of the inherent weaknesses of using the accounts of others might be overcome by ensuring that all of the relevant literature was used, even accounts of unsuccessful studies and evidence from unpublished studies, and then conducting a full meta-analysis of the results (I recommend using a Bayesian approach, see appendix to Gorard et al. 2004, which allows the relatively simple combination of different kinds of evidence). But such systematic reviews of evidence are rare, very difficult to do properly, and both expensive and time-consuming. And, anyway, this second approach does not overcome the chief drawbacks of the literature, which are that we have no direct access to the evidence of others, and often face a very partial view of the assumptions made and the analyses conducted. Much better, in many ways, is the approach of collecting primary data yourself and con-
ducting the cleaning, coding and analysis yourself. This third kind of evidence overcomes many of the drawbacks you will encounter in trying to understand what other people have done from their own accounts (but try to remember to make your own accounts suitably clear about the assumptions, short cuts and compromises you have made). It is probably true to say that most education researchers use primary evidence at some stage, just as most of them conduct reviews of literature. The drawbacks of generating primary evidence include the time and cost involved, and so the likely small scale of your own study. A compromise, used by only a minority of social science researchers at present, lies in
the reanalysis of secondary data. Secondary data has been generated by others, but is
available directly to new researchers to conduct their own analyses. Many of the techniques, craft tips, and issues covered in this chapter may have applications beyond the use of secondary data, but secondary data is the focus of what follows. I consider, in turn, some of the likely sources of this fourth kind of evidence, why all of us should perhaps be using secondary evidence more, and how such data might be analysed.
