The surge of learners being immersed in computer game contexts for learning has instigated dialogue about the contextually appropriate collection of reliable and valid data to inform education-based decisions. The purpose of this article is to develop educational practitioners' understanding of preliminary research work, and to inform educational researchers about design and reporting of preliminary research work, in the context of reported preliminary studies on Digital Game-Based Learning Interventions (DGBLIs). First a checklist of processes for the reporting of preliminary studies is provided. Second, a summary is offered of the characteristics of each type of preliminary study including the description, objectives, and methodology. Third, an example from peer-reviewed literature is identified of each type of preliminary study relevant to DGBLIs and conducted within the past five years. Evident from the examples selected, educational researchers and practitioners are best advised to recognize the characteristics of preliminary studies -- pilot work, feasibility study, pilot study, pilot trial, and field test -- to better inform DGBLIs before embarking on a full-scale study, and to meet the need of educational practitioners for concrete evidence about DGBLIs.