Large-scale analyses are a powerful and increasingly common tool for investigating a range of public health and social concerns (Pienta, O'Rourke, & Franks, 2011). This series will provide a primer on large-scale secondary analysis in school psychology, with this article focusing on considerations for researchers interested in applying and reporting on large-scale analyses. It discusses the advantages of this type of analyses, limitations to be aware of, and other considerations for researchers. Part 2 will provide guidance for school psychologists as consumers, including guidelines for evaluating the quality of secondary analyses and deriving practical applications. Part 3 will discuss issues involved with dissemination of these kinds of analyses in social media and other channels outside of journals.