Which scores align best with what you know to be true about his reading?
My son, who began reading at age 2 and who could read essentially anything you put in front of him by age 7 had his reading comprehension scores on the ITBS (paper and pencil achievement test) get progressively worse for several years in a row in middle childhood. I finally discovered that he was skipping the passages and just answering the questions. When I forced him to read the test and questions aloud (as a homeschooler I administered the test myself at home), his score went right back up to the 90 something percentile (on a test that was three years above age-grade level).
So there's that possibility.
