Cooperative Learning Contingencies: Unrelated versus Related Individual and Group Contingencies
College students operating under related cooperative contingencies (students had to earn individual credit before being considered for group credit) showed more consistent individual and group improvement on exam performance than students operating under unrelated contingencies (individual credit and group credit were independently determined). A balanced ratio between individual and group credit proved to be the most productive ratio under the related contingency, whereas a ratio favoring group credit over individual credit proved most productive under the unrelated contingency. In general, a ratio favoring individual credit over group credit was the least productive in promoting both individual and group improvement under both unrelated and related contingencies. The findings showed less difference in improvement of exam scores for students of different performance levels than had been evident in previous research.
Bob Williams, Erin Carroll, and Briana Hautau. "Cooperative Learning Contingencies: Unrelated versus Related Individual and Group Contingencies" Journal of Behavioral Education 15.4 (2006): 191-202.