The use of student response systems is becoming more prevalent in higher level education. Evidence on the effectiveness of this technology can be an important resource for tutors seeking to engage with learners and raise the quality of learning experiences. Student response systems have been found to increase student engagement and participation in the classroom, yet few studies examine why this is so. This research seeks to explore the effects of student response systems on student participation in large classes. The methods used included both quantitative and qualitative data. A pre-test/mid-test/post-test design (quantitative approach) was deployed to examine the effects of a classroom response system on interactivity. Students involved in a final year undergraduate business course took part in investigating the use of student response systems from the student perspective. Qualitative data were collected to identify the strengths and weaknesses of using a classroom response system to enhance classroom interaction through semi-structured interviews. This research builds on previous studies by investigating why students become more participatory, interactive and engaged during learning sessions which utilise student response systems. Implications for teaching practice are discussed, and avenues for future research on student response systems and student engagement in large class scenarios are outlined.