Can anonymous written feedback collected during classroom assessment activities be used to assess students' cognitive development levels? After library instruction in a first-year engineering design class, students submitted minute papers that included answers to "what they are left wondering." Responses were coded into low, medium and high categories correlated to cognitive stages following a codebook that was developed based largely on Perry's model and on two semesters' worth of prior student feedback. Preliminary analysis suggests that subjects exhibit characteristics in keeping with the range of cognitive levels identified by previous research at this institution, but that they tend to be weighted toward the lower end of the spectrum. While this study does not reveal cognitive development levels as reliably as the work of previous researchers, it does propose an easy method for identifying general cognitive development levels of student cohorts and offers recommendations for using this knowledge to improve instructional effectiveness.