1frugalmom, I don't know much about the explore, but when my daughter took her grade level achievement test in 3rd grade, she didn't do super great on reading, and did better in math, and she is a very verbal kid who reads a ton with great comprehension. I'm not sure what happened, but I wonder if a kid reads high level books for enjoyment and gets the nuance, etc, maybe reading dry passages and then "identifying the main idea" or whatever doesn't really hold their interest. I'm not sure that a reading comp test can ever really accurately measure the way a sophisticated reader who loves reading integrates a text. Maybe?