As a few different reading experts have told me, if your very young child is able to decode text at a high level, his decoding level obviously doesn't match his comprehension level. These are two different metrics, and while I've been using
http://homeschooling.gomilpitas.com/articles/060899.htm as a quick rule of thumb for decoding level, the tests for comprehension level are not free (as far as I know) and much more difficult to take, especially for a little kid. For purposes of comprehension, I think it's reasonable to say that if your child can understand, without much clarification on your part, most books that are of a certain reading level according to the Scholastic Book Wizard (
http://bookwizard.scholastic.com/tbw/homePage.do), then your child is reading at that level. So I figure I can read books to him that are above his comprehension level, so long as I explain difficult words as we read, and sometimes we read simple books that require little or no clarification. But more often, he just reads those books himself--earlier today,
Flat Stanley, grade level 4.4. And it's very vague anyway, by this measure, because as H. told me when I observed that he didn't need me to explain much from the book, he flipped to a phrase he didn't understand. He was also reading The Last of the Really Great Whangdoodles (grade level 7.3) to me while I snoozed, and so didn't seem to need much help from me with word definitions, but I know it has a lot of words that are challenging for him. And the grade levels are not AT ALL reliable. "Whangdoodles" might have measured at a 7.3, or allegedly appropriate for 12-year-olds, probably due to vocabulary, but in every other respect it is totally accessible to much younger children. I myself read it the first time when I was nine, and I don't remember having too much trouble with it.