I'm on the 4th principle of 6 in chapter 2. I've found this section problematic starting with the very first sentence: "...one of the most interesting characteristics of background knowledge is that it does not have to be detailed to be useful."
Detail, or lack thereof, would be a characteristic of background knowledge. But the first sentence doesn't say that. It is an implication of the research about background knowledge, but it isn't a characteristic of background knowledge itself.
My point isn't to be petty. It's to point out that there is a reason that this book is difficult to read. In many places it's not written clearly. Another example is the Collins and Quillian research he mentions in this section--in a completely circular way. Marzano writes, "If it is true that information closest to the top of the hierarchy is the most available, then we should remember the top-level information more quickly..." That's if. That means it is a supposition that needs testing.
Later he says, "Time taken to validate the accuracy of a sentence was considered an indication of the information's place within the hierarchy." But I thought that was the "if" part. So, we know that subjects in the experiment took more time to validate the accuracy of some statements than others. But we don't know IF that means it is an indication of that information's place in the hierarchy.
I'm having difficulty with his comparison of the hierarchy of the knowledge ofa word and the taxonomies of knowing vocabulary words. They don't seem to match up. If they do, Marzano has not been able to elucidate that point adequately.
I am finding some interesting ideas in this book, but there's so much chaff that it's difficult to find and perceive the grain.