Assessment methods across post-secondary STEM education are traditionally constrained by logistics and likely contribute to the widespread inequities in STEM education outcomes. As part of attempts to improve and diversify the methods used in assessment, the authors have developed a flexible and low-tech style known as 'public exams' based in educational best practices. Public exams attempt to involve students authentically into the process of assessment through the use of pre-released portions of the exam. Through an initial mixed-methods research endeavor at a closely-matched pair of a research-intensive university and a community college classroom, we observe signals of positive impact from the public exam on student experiences. Public exams appear to promote deeper thought, to direct students more efficiently to the core concepts in the discipline, and may decrease student anxiety around exams. The public exam experience does not show evidence for exacerbating gaps in exam outcomes for students from underrepresented backgrounds. This evidence suggests that public exams are worth deeper investigation as an evidence-based and effective assessment style.