Student Response Systems

http://www.dell.com/learn/us/en/26/k-12-solutions-featured-solutions-instructional-technology-student-response-systems
http://www.prometheanworld.com/us/english/education/products/assessment-and-student-response/
http://learninginhand.com/blog/four-student-response-systems.html
http://www.einstruction.com/srs-overview
http://tccl.rit.albany.edu/knilt/index.php/Unit_2:_Why_Use_Student_Response_Systems%3F
http://en.wikibooks.org/wiki/Computer_Information_Systems_in_Education/Chapter_3/Section_1_--_Student_Response_Systems