Case Studies and Theory Development in the Social Sciences - Alexander L. George [50]
The Provisional Character of Case Explanations
Case explanations must always be considered to be of a provisional character. Therefore, the theoretical conclusions drawn from case study findings (in phase three) will also be provisional. The explanations provided by the case writer may be challenged by other scholars on one or another ground—for example, the original research may have overlooked relevant data or misunderstood its significance, failed to consider an important rival hypothesis, and so forth. If case explanations are later successfully challenged, the researcher will have to reassess the implications for any theory that has been developed or tested. Such a reassessment would also be necessary if new historical data bearing on the cases become available at a later date and lead to a successful challenge of earlier explanations.
In seeking to formulate an explanation for the outcome in each case, the investigator employs the historian’s method of causal imputation, which differs from the mode of causal inference in statistical-correlational studies. These causal interpretations gain plausibility if they are consistent with the available data and if they can be supported by relevant generalizations for which a measure of validity can be claimed on the basis of existing studies. The plausibility of an explanation is enhanced to the extent that alternative explanations are considered and found to be less consistent with the data, or less supportable by available generalizations.
An investigator must demonstrate that he or she has seriously considered alternative explanations for the case outcome in order to avoid providing the basis for a suspicion, justified or not, that he or she has “imposed” a favored theory or hypothesis as the explanation. Such a challenge is likely if the reader believes that case selection was biased by the investigator’s commitment to a particular theory or hypothesis.188
The Problem of Competing Explanations
A familiar challenge that case study methods encounter is to reconcile, if possible, conflicting interpretations of a case or to choose between them. This problem can arise when the investigator provides an explanation that differs from an earlier scholar’s but does not adequately demonstrate the superiority of the new interpretation. As Olav Njølstad notes, competing explanations may arise from several sources.189 There are different types of explanation stemming, for example, from historiographical issues such as the relative importance of ideology or historical context. Sometimes competing explanations can be equally consistent with the available historical evidence; this makes it difficult to decide which is the correct explanation or, alternatively, whether both interpretations may be part of the overall explanation—i.e., whether the outcome may be overdetermined. Another possibility is that each of the ostensibly competing explanations in fact addresses different parts of a complex longitudinal development. In such cases, the task of the investigator is to identify different turning points in the causal chain and to sort out which independent variables explain each step in the causal chain—for example, those explaining why a war occurred, those that explain the form of the attack, those that explain its timing, and so on. Still another possibility is that the key variable in one explanation is causal and the proposed causal variable in the other explanation is spurious.
The problem of apparently competing explanations may also arise when the rival interpretations address and attempt to explain different aspects of a case and therefore cannot be reconciled. When this happens, the