Demo Hour


Issue: XX.4 July + August 2013
Page: 8
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Andrew Cross, Ed Cutrell, and Bill Thies

qCards are an inexpensive way to engage large audiences through interactive polling. When asked a multiple-choice question, audience members raise their qCards, sheets of paper with a unique identifier on the front, in one of four possible orientations corresponding to A, B, C, or D written on the back. Using computer vision, a camera recognizes each qCard ID and multiple-choice response and aggregates the poll results for the presenter to review or display.

qCards debuted at the 2012 ACM User Interface Software and Technology conference polling roughly 300 people, capturing 90 percent of responses and with 98 percent accuracy.

Project website:


Publication: Cross, A., Cutrell, E., and Thies, W. Low-cost audience polling using computer vision. Proc. of the 25th Annual ACM Symposium on User Interface Software and Technology. ACM, New York 2012, 45–54.

Andrew Cross | Microsoft Research India | [email protected]

Ed Cutrell | Microsoft Research India | [email protected]

Bill Thies | Microsoft Research India | [email protected]