Reviews of the literature are frequently advocated to advance knowledge in the social sciences. Unfortunately, most reviewers do not explicitly consider or attempt to learn from what previous reviewers of the same or closely related topics have done. This omission is inconsistent with good scientific practice and is significantly detrimental to advancing knowledge. Using 52 previous reviews of the early intervention efficacy literature as an example, this article demonstrates the value of systematically considering previous reviews before initiating a new review. The results establish a foundation that should be particularly helpful to future reviewers of the early intervention efficacy literature and demonstrate a process that should be used by reviewers in all areas.The process of scientific inquiry presupposes that scientists will carefully consider what other scientists have done in the same or closely related areas (Kuhn, 1962). Such an analysis serves three general purposes. First, an examination of previous work helps to determine whether there is a need for further scientific inquiry. Second, understanding what is known in a particular area is necessary so that ongoing work can be appropriately delimited and is not inconsistent with or unnecessarily duplicative of established facts. Finally, an examination of previous work often results in insights which can be used to improve the procedures for the work being planned. In this way, procedural strengths of previous work can be emphasized and weaknesses avoided.The value of reviewing previous work in the same or related areas is widely recognized. Consequently, almost all reports of primary research from theses and dissertations to articles published in referred journals begin with a brief &dquo;review of the literature.&dquo;The parallels between conducting primary research and attempting to integrate and draw conclusions from previously completed Downloaded from 418 topics is seldom done in reports of &dquo;literature reviews.&dquo; For example, in an analysis of 52 reviews of the early intervention efficacy literature, we found that only 10 reviewers cited more than three previous reviews, and nobody critically examined the procedures and conclusions of previous reviews and described how their review would differ from or improve on previous work. Similar results were reported by White, Baer, and Myette (1982) in their analysis of the literature on interventions for hyperactivity.Using the literature on the efficacy of early intervention as an example, the purpose of this paper is to demonstrate the value of systematically analyzing previous reviews of the literature as an initial step in conducting an integrative review.