In summary, explanations based on case studies involve much more than explaining variation in one variable in terms of variation in another variable. Case study designs are devised to yield a sensible, plausible account of events and in this way achieve internal validity. They achieve explanations by building a full picture of the sequence of events, the context in which they occur, and the meaning of actions and events as interpreted by participants and their meaning as given by a context. In the end an adequate causal explanation is one that makes sense. It involves telling a plausible, convincing, and logically acceptable story of how events unfold and how they are linked to one another.
History and maturation
The way in which ‘history’ and maturation can threaten the validity of causal explanations has been discussed in previous chapters. Experimental designs seek to deal with the problems of history and maturation by using randomized control-groups and focusing on differences in change between these group rather than on absolute changes (Chapters4 and 5).
Case study designs try to deal with the ‘problem of history’ and maturation by looking closely at the wider context and exploring the extent to which these sorts of concurrent events contribute to observed outcomes. That is, rather than elimination historical/contextual and maturational factors from the analysis (by controlling them out) the case study designs include them in order to enhance our understanding. In this way we can arrive at a fuller and richer understanding while, at the same time, avoiding the threats that history and maturation present to the internal validity of our case study conclusions. The quality of the case study will validity of our case study conclusions. The quality of the case study will largely rest on how well it identifies these historical/ contextual and maturational factors and includes them in any explanation.
Reactive effects