University of the Pacific librarians used personal response systems (PRS) or clickers in first- year mandatory library instructional sessions to assess their effects on student engagement and retention of learning outcomes. Students who utilized clickers during their library sessions reported greater enjoyment and encouragement to participate (n=291). Students in the sessions not utilizing the clickers achieved better learning outcomes than their counterparts who utilized clickers (n=326). The implications of these results are discussed, specifically within the context of pedagogy and tailoring instruction to the Millennial generation.