There are endless books about what every third grader must know that use the idea that factual knowledge is the basis of the ability to read as their justification. Unfortunately, the writers of these tracts have misunderstood the cognitive science behind those statements. It is difficult to read things when you don't understand what they are about, but it does not follow from that thatthe solution is to ram that knowledge down kids' throats and then have them read. It is much more clever to have them read about what they know and to gradually increase their knowledge through stories that cause them to have to learn more in order to make the stories understandable to them.