On Types of Scientific Inquiry: The Role of Qualitative Reasoning

Abstract

. One type of scientific inquiry involves the analysis of large data sets, often using statistical models and formal tests of hypotheses. Large observational studies have, for example, led to important progress in health science. However, in fields ranging from epidemiology to political science, other types of scientific inquiry are also productive. Informal reasoning, qualitative insights, and the creation of novel data sets that require deep substantive knowledge and a great expenditure of effort and shoe leather have pivotal roles. Many breakthroughs came from recognizing anomalies and capitalizing on accidents, which require immersion in the subject. Progress means refuting old ideas if they are wrong, developing new ideas that are better, and testing both. Qualitative insights can play a key role in all three tasks. Combining the qualitative and the quantitative–and a healthy dose of skepticism–may provide the most secure results.