迈向理论导向的个案研究:过程追踪与一致性分析的混合设计

Toward a Theory-Oriented Single Case Study:A Mixed Research Design Using Process-tracing and Congruence Analysis

近年来,案例研究受到越来越多的重视。在公共政策与公共管理领域,采用案例研究方法的文章又以个案研究居多。这些研究都有“重叙述、轻因果”的共同特点,即把案例作为一种描述性工具,试图在一系列事实的基础上创造一些看似新的概念来作出贡献。尽管这类个案研究的价值毋庸置疑,但是它们掩盖了个案研究在因果推断方面的重要功能。为了弥补现有文献的这一局限,本文提出,将过程追踪法与一致性分析法相结合的混合研究设计是一种在个案中开展因果推断的有效途径。过程追踪法旨在通过识别机制进行因果推断,而一致性分析法则更有助于排除其他竞争性解释,因此,整合二者的混合方法设计将会助益以因果关系与因果机制为中心的解释性个案研究。本文在讨论了过程追踪法与一致性分析法的基本思路基础上,为这一混合研究设计提供了一份清晰的操作清单。此外,本文也通过与少案例比较法和定性比较分析法等案例导向方法对比,以揭示过程追踪法和一致性分析法的鲜明特点,从而阐明这一混合方法设计的优势与潜在局限。最后,正是在这种强调“因果”与“解释”的意义上,我们呼吁未来出现更多以理论为导向的个案研究。

In recent years,case studies have been rediscovered and have assumed a position that is as important as quantitative methods.Against this background,an increasing number of research articles using case study methods have been published in Chinese public policy and administration journals.Among these,single case studies account for a large,if not the largest,proportion.These studies share the common feature that they use the case as a descriptive tool,attempting to make contributions by creating some seemingly new concepts based on a collection of facts.Despite their value,they have rarely made causal inferences with a single case,thus obscuring an important function of case studies.In order to remedy this limitation in the existing literature,this article introduces a mixed research design for single case studies by using both a processtracing method and congruence analysis.From the essence of these two methods,it can be seen that process-tracing methods are very helpful in making causal inferences through the identification of mechanisms,while congruence analysis is better at ruling out other alternative explanations.As a result,combining process-tracing methods with congruence analysis is an effective research design for scholars to come up with scientific explanations based on a single case.It is in this sense of causalities and explanations that we are appealing for theory-oriented single case studies.