Life science faculty who wish to know if their students are mastering science process and reasoning skills, such as experimental design, graphing, data analysis, and science communication, have very few assessment options. We developed the Scientific Process and Reasoning Skills Test (SPARST) to assess these skills in a biology content-independent but context-dependent manner. SPARST was designed to assess students’ acquisition of science process and reasoning skills throughout their undergraduate biology education. SPARST consists of four modules – Data Analysis, Experimental Design, Graphing, and Science Communication – that each take 30 minutes for students to complete and can be scored separately from the other modules. The modules are multiple-choice and are administered and graded online. Here we describe the development process and Item Response Theory analyses of pilot results. Our pilot data shows that SPARST is discriminating between all four academic years. Once SPARST is finalized, we will conduct a large national study and broadly disseminate our findings and the instrument.