As a pilot study, hand-held personal response systems (PRS) using radio frequency response devices, i.e. clickers, were implemented in several courses at the University of Missouri-Rolla. Within the Chemical and Biological Engineering Department the courses included the sophomore level material balances course, a senior level reactor design course and a graduate level advanced reactor design course. The PRS software was set up to incorporate slides into regular PowerPoint presentations in which questions could be asked and in which the students could immediately respond. The software offers students a visual clue that their clicker response have been recorded. The RPS automatically shows the student response on the screen, and after polling produces a graph of the student responses. This leads to instant feedback to both the instructor and students and can be used to modify the direction and topics of the lecture/activity. The PRS has been used to quiz students over reading assignments at the beginning of class and to check students' comprehension of the material presented. The PRS also helps to engage the students in the lecture/activity and maintain their attention during class. The various questions and responses are automatically recorded and can be assigned points to be added to the grade book if desired. One application used the PRS primarily to ask questions over the assigned reading. Students came to class having read the assignment, and their level of understanding and assimilation was evident from their responses. This feedback indicated to the instructor that more time covering the topic content would be necessary if it was evident that much of the class was unclear about the answers, or the instructor could spend time on examples or additional topics. In the past the instructor could ask whether students understood, but it was hard to have a measurable response to the level or extent of understanding by the students. With the PRS it was clearly evident what portion of the students understood the various topics tested on. Generally the students responded favorably to the PRS technology. They felt that it encouraged them to stay current on the reading assignments and also broke up the class time and kept things interesting. Lessons learned and student responses will be described.