Howard Wainer, a statistician with the Educational Testing Service, recounted the following [19]: My phone rang just before Thanksgiving. On the other end was Leona Thurstone; she is involved in program evaluation and planning for the Akebono School (a private school) in Honolulu. Ms. Thurstone explained that the school was being criticized by one of the trustees because the school’s first graders who finish at or beyond the 90th percentile nationally in reading slip to the 70th percentile by 4th grade. This was viewed as a failure in their education.…I suggested that it might be informative to examine the heights of the tallest first graders when they reached fourth grade. She politely responded that I wasn’t being helpful.

Explain his suggestion.