Opportunities to Respond (OTR)
Response Cards
(Taken from http://www.interventioncentral.org/index.php/general-academic/89-group-response-techniques)
Students can respond as a group by displaying 'response cards' which display their answers to a teacher question or academic problem. Two response-card formats may be used: (1) cards with pre-printed response choices (e.g., YES/NO; True/False, a,b,c, & d; 1,2,3, & 4) and (2) cards/whiteboards/chalkboards on which students write their responses.
Irrespective of the type of card format used, the teacher should introduce response cards by explaining and demonstrating their use and letting students practice the response procedure until they are proficient in using the cards. The instructor should maintain a quick, lively pace through the lesson, providing clear clues about when the students should hold up or put down their cards. Some students will inevitably offer an incorrect answer; the instructor should simply focus on, and provide feedback for, the majority response.
If pre-printed response cards are used, the instructor will have the best results if the cards contain items that are clearly legible from the front of the room, are designed to be easy for 
students to manipulate and display to the teacher, and have sufficiently few items to prevent students from becoming confused. (Additional items or cards can be added to the class's routine as students master the use of the cards.)
If write-on response cards are used, it is best to limit responses to 1 to 2 words if possible. Students may shy away from writing, or be slowed down, by problems with spelling. Among useful strategies to reduce spelling difficulties, the instructor could:
- have students 'pre-practice' the spelling of new vocabulary words prior to the lesson
- post unfamiliar spelling terms on the board for students to refer to as they write their responses, or
- encourage students to try their best in spelling their responses but reassure them that misspellings will not be counted against them.
Teachers can see for themselves the relationship between providing opportunities to respond for students and student achievement. First consider, keeping a baseline of what your normal practice was; then use different models of opportunities to respond and keep data for 15 minutes on the number of student responses you received using this method. (A sample is provided here).
(The chart was taken from Moore- Partin, Robertson, Maggin, Oliver, & Wehby, 2010).
What the research says (in a nutshell): When teachers increase the rates of opportunities to respond, student on-task behavior and correct responses increase, while student disruptive behavior decrease.