The purpose of this study was to examine the effects of Laban Effort Action (slash) instruction in an undergraduate conducting class on college wind ensemble member's ratings of conductors' gestural clarity. Participants--undergraduate and graduate wind ensemble members (N = 28)--rated 32 videos of eight undergraduate conducting students who had received instruction in the Laban Effort Action slash (twice pre-treatment, twice post-treatment) using the researcher-designed Gestural Clarity Rating Instrument (GCRI) for gestural accuracy and gestural appropriateness. Raters reported statistically significant increases in conducting students' gestural accuracy and appropriateness before and after treatment. However, it is unlikely the treatment caused the increase in scores. Raters reported relatively steady gains in both gestural accuracy and appropriateness between the first three chronological observations. Conducting educators may not wish to let Laban Effort Action instruction comprise the bulk of their curricula, though clarity may be a valid and reliable domain for assessing undergraduate student conductors.