REEF was one of five citizen science (CS) project teams that participated in a multi-year study funded by the National Science Foundation to understand CS volunteers’ accuracy and skills. This paper is the culmination of that study, which included several facilitated exercises and meetings between external researchers and the project participants. The CS teams identified a wide range of skill variables that were “hiding in plain sight” in their data records that could be explored as part of a secondary analysis. Each team identified a small number of evaluation questions to explore with their existing data. REEF's "hiding in plain sight" was using surveys collected in different scenarios (solo surveyor, surveying with a buddy, surveying in a group during a REEF Trip) to evaluate skill gains as measured by the number of species reported on each survey. The results from these analyses were then used to inform the design of both existing and new CS projects, and to inform the field more broadly through a range of dissemination strategies.