What the design should do is eliminate (or at least test or allow for) the greatest
possible number of alternate explanations. In this way, the design eases the analysis
process, and provides part of the warrant for the research claims.
What all of these designs, and variants of them, have in common is that they do not
specify the kind of data to be used or collected. At the level of an individual study,
the research design used by social scientists will be independent of, and logically
prior to, the methods of data collection and analysis employed. No kinds of data, and
no particular philosophical predicates, are entailed by common existing design
structures such as longitudinal, case study, randomised controlled trial, or action
research. A good intervention, for example, could and should use a variety of data
collection techniques to understand whether something works, how to improve it, or
why it does not work. Experiments can use any kind of data as outcomes, and collect
any kind of data throughout to help understand why the outcomes are as they are.
Longitudinal studies can collect data of all types over time. Case studies involve
immersion in one real-life scenario, collecting data of any kind ranging from existing
records to ad hoc observations. And so on.
Mixed methods approaches are therefore not a kind of research design; nor do they
entail or privilege a particular design. Of course, all stages in research can be said to
involve elements of ‘design’. The sample design is one example, and the design of
instruments for data collection another. But research design, as usually defined in
social science research, and as discussed here, is a prior stage to each of these (de
Vaus, 2001).
The cycle of research
At the meta-level of a programme of research conducted by one team, or a field of
research conducted by otherwise separate teams, the over-arching research design
will incorporate most methods of data collection and analysis. Figure 1 is a simplified
description of a full cycle for a research programme (for a fuller description and
discussion, see Middleton, Gorard, Taylor, & Bannan- Ritland, 2008). It is based on a
number of sources, including the genesis of a design study (Gorard with Taylor,