Our district's G/T magnet school also re-tests achievement and ability as kids progress through school to re-qualify the children, and I've known children who were admitted in kindergarten and later sent elsewhere because the earlier scores didn't hold up and their teachers felt they were not properly placed in the program.
sorry to go OT, but this is so interesting to me. I didn't think there were districts out there that dared to do this. How do the parents react if a child is disqualified after qualifying initially?
(My DD also attends a gifted magnet. AFAIK, her half-hour IQ test at 6 will continue to qualify her for GT programs through high school and she will never be retested. I feel lucky she got in, and at the same time I really do wonder how accurate it all is.)