Persuasion with case studies

The goal of every author is to write a paper that readers (and reviewers) find convincing. Since writers of papers based on case research do not have recourse to the canonical statement “results are significant at p 0.05” that helps assuage readers’ skepticism of empirical papers, researchers using case research often feel they are fighting an uphill battle to persuade their readers. In this short essay, I provide some thoughts guided by my experience of reading, reviewing, and writing papers based on case-based research over the last decade. These are clearly only the views of this particular writer and thus should be taken with a considerable grain of salt. I am seeking here more to provoke thought than to provide answers. What makes a case study persuasive? The first big obstacle that many writers feel they face is the charge of having too small a sample. Yet, imagine the following scenario, adapted from Ramachandran (1998): You cart a pig into my living room and tell me that it can talk. I say, “Oh really? Show me.” You snap with your fingers and the pig starts talking. I say, “Wow, you should write a paper about this.” You write up your case report and send it to a journal. What will the reviewers say? Will the reviewers respond with “Interesting, but that’s just one pig. Show me a few more and then I might believe you”? I think we would agree that that would be a silly response. A single case can be a very powerful example. Perhaps not surprisingly, the management field is not alone in its debate about the value of smallversus large-sample research. In neurology, where a lot of knowledge has been gleaned from case studies of individual patients with particular brain injuries (lesions), a similar debate is underway. Ramachandran, a prominent neurologist, uses the example above to make his case for case research. So should we now rejoice and simply cite Ramachandran to motivate and justify our case-based research? Well, we had better not forget that the above scenario involved a talking pig. That was quite a deal. Thus, my first main point is that if you want to write a case study that derives its excitement and justification through little more than the description of a particular phenomenon, make sure you have a talking pig. If not, a purely descriptive study will be a hard sell. The second charge that case-based researchers often feel obliged to defend themselves against is that of nonrepresentativeness. “You have a biased sample,” reviewers might say. Let us again have a quick look at the field of neurology. One of the most celebrated case studies in that field is of a man named Phineas Gage. Living in the second half of the 19th century, Gage was the foreman of a construction crew preparing the bed for a new railroad line. Part of his job was to fill holes, first with gunpowder and then with sand, which was then packed in with a large tamping iron. Unfortunately, at one hole Gage forgot the sand, created a spark with his tamping iron, and ignited the charge. The tamping iron, weighing thirteen and a half pounds, shot through his head, landing 30 yards behind him. Remarkably, Gage survived and continued to live for 12 more years, despite the large hole in his head and major destruction to his brain’s frontal lobes. However, both psychologically and behaviorally, he was a changed man. For example, while he had previously been considered a smart man who energetically executed his plans, he now was capricious and vacillating, devising many plans but not following through with any of them. Similarly, whereas before he had been described as having a temperate personality, he was now impatient and profane, particularly when advice given to him conflicted with his desires. These psychological and behavioral changes led observers to draw inferences about what functions might be performed by the frontal lobes.