We have conducted an investigation into how well students in introductory science classes (both physics
and chemistry) are able to predict which questions they will or will not be able to answer correctly on an
upcoming assessment. An examination of the data at the level of students’ overall scores reveals results
consistent with the Dunning-Kruger effect, in which low-performing students tend to overestimate their
abilities, while high-performing students estimate their abilities more accurately. Similar results have been
widely reported in the science education literature. Breaking results out by students’ responses to individual
questions, however, reveals that students of all ability levels have difficulty distinguishing questions which
they are able to answer correctly from those that they are not able to answer correctly. These results have
implications for the future study and reporting of students’ metacognitive abilities.