Developing Open-Source Databases from Online Sources to Study Online and Offline Phenomena

Open-source data is increasingly a source for studying criminal justice issues, especially those pertaining to hard-to-reach populations. Despite the growing popularity of open-source databases, relatively little research has assessed the process of database development, measured the reliability and validity of the end products, or attempted to introduce standardized guidelines for open-source data collection. This chapter aims to address these gaps. First, it reviews the necessary steps for creating an open-source database, including identifying cases, defining the source universe, establishing a search protocol, training searchers and coders, developing a codebook, coding cases, and more. The chapter then reviews issues of reliability and validity that arise before, during, and after database development, and outlines best practices for maximizing both reliability and validity. Additional guidelines related to using diverse types of open-source data and applying open-source data collection to online and offline criminal justice phenomena are also discussed.