Numerous studies have shown that training students in self-questioning enhances comprehension (Andre and Anderson, 1979; Nolte and Singer, 1985; Palincsar, 1984; Singer and Donlan, 1982; Yopp, 1987). As Singer (1978) and Yopp (1988) have argued, the process of self-questioning, or active comprehension, facilitates comprehension because it requires students to use their metacognitive capacities and activates their background knowledge.
Yopp, R. H., & Deher, M. J. (1994). Effects of Active Comprehension Instruction on Attitudes and Motivation in Reading. Reading Horizons, 34 (4). Retrieved from http://scholarworks.wmich.edu/reading_horizons/vol34/iss4/1