Now that we're looking at a much larger sample of elementary and special ed programs as part of our
, it's clear that there really isn't an accepted body of literature to instruct candidates on the skill of teaching kids how to read. To date we've reviewed over 1030 different reading textbooks and new ones continue to pop up.
It seems like a field, be it science, math, education or any other, should have consensus at least on what's taught in its foundational courses, so the sheer quantity of reading textbooks in use has always surprised us. We decided to do a little experiment to test the hypothesis that this situation is fairly unique.
First, we looked at required textbooks for introductory undergraduate courses across the subjects of calculus, biology and reading at 30 randomly chosen institutions. After counting how many unique textbooks were required, the three fields appeared relatively similar. The textbook requirements from a second set of randomly chosen institutions were then compared to the first. We counted from that second set how many additional unique textbooks emerged. Within calculus and biology, the number dropped off significantly by about a third and a half respectively. Unique reading textbooks, however, appeared at the same rate as in the first set.
If the growth rate held for another few rounds, we predict that the number of unique calculus textbooks would eventually settle at around 70 total textbooks, give or take a few. For biology, it would settle at about 45. (And this in a field undergoing monumental changes in areas such as genetics.)
Reading textbooks though, as we have found in our work, are in seemingly endless supply. Quality discussions aside, the sheer quantity relative to other fields suggests a serious lack of consensus.