Reading rewards study

This study investigates the impact of rewards on reading behavior in the short run: After children did a short reading activity, providing no reward or providing a book as a reward resulted in much more actual reading during a short “free choice” period than providing a non-book award (e.g. Nerf balls, Pez dispensers, key chains). According to Krashen's calculations, there was a slight tendency for no-award to stimulate more reading than the book award, but both were much more effective than providing a non-book award.
Marinak, B. and Gambrell, L. 2008. Intrinsic motivation and rewards: What sustains young children's engagement with text? Literacy Research and Instruction, 47 (1): 9–26.

Reported by S.  Krashen