These are the current major companies that make response systems. Product details, tutorials, downloads, and contact information are provided on the company web sites. Barber and Njus (2007) and Burnstein and Lederman (2003) offer reviews of the clicker technology available.
eInstruction Personal Response System. Students using PRS make a one-time purchase of their transmitter at the bookstore or some other retail outlet. The same student can use the transmitter for multiple classes in the same semester or over multiple semesters.
eInstruction Classroom Performance System. Students using CPS make both a one-time purchase of their transmitter plus a semester registration fee.
iClicker. These clickers are limited with the types of questions but instructors and students like the simplicity that comes with the system.
Turning Technologies. Students also make one-time purchases for these clickers.
Qwizdom. Students also make one-time purchases for these clickers.