  The existence of gender differences in student performance on conceptual
assessments and their responses to attitudinal assessments has been repeatedly
demonstrated. This difference is often present in students' preinstruction
responses and persists in their postinstruction responses. However, one area in
which the presence of gender differences has not been extensively explored is
undergraduate laboratory courses. For example, one of the few laboratory
focused research-based assessments, the Colorado Learning Attitudes about
Science Survey for Experimental Physics (E-CLASS), has not been tested for the
existence of gender differences in students' responses. Here, we utilize a
national data set of responses to the E-CLASS to determine if they demonstrate
significant gender differences. We also investigate how these differences vary
along multiple student and course demographic slices, including course level
(first-year vs.\ beyond-first-year) and major (physics vs.\ non-physics). We
observe a gender gap in pre- and postinstruction E-CLASS scores in the
aggregate data both for the overall score and for most items individually.
However, for some subpopulations (e.g., beyond-first-year students) the size or
even existence of the gender gap depends on another dimension (e.g., student
major). We also find that for all groups the gap in postinstruction scores
vanishes or is greatly reduced when controlling for preinstruction scores,
course level, and student major.
