“McGrewâ€™s findings donâ€™t apply only to those with IQs in the 70â€“80 range. No matter what IQ band you pull out from McGrewâ€™s analysis, youâ€™ll find the same thing. In fact, a law emerges. Using the most reliable IQ tests available today, McGrew notes that â€œfor any given IQ test score, half of the students will obtain achievement scores at or below their IQ score. Conversely, and frequently not recognized, is that for any given IQ test score, half of the students will obtain achievement scores at or above their IQ score.â€ Clearly a childâ€™s current discrepancy between IQ and achievement doesnâ€™t necessarily indicate a learning disability.
But perhaps the biggest flaw in the severe discrepancy method is that itâ€™s a fundamentally unintelligent method. It treats single IQ scores as the arbiter of truth, without looking at the personâ€™s history and understanding the numbers in context. Responsible and intelligent use of IQ tests require us to consider the studentâ€™s overall pattern of strengths and weaknesses (not just on the IQ test but even more generally in terms of talents, and social and emotional functioning), life aspirations, developmental history, environmental circumstances, and opportunities to learn.”
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