<p>supporting bc’s point about the statistical problem with USN’s practice of adding the SAT M quartile & SAT CR quartile, to represent the 25-75 range for combined scores, I recall one college’s factbook that reports both ways…Colby.</p>
<p>Here’s their 2008 factbook:
<a href=“http://www.colby.edu/administration_cs/ir/factbook2008/upload/Admissions.pdf[/url]”>http://www.colby.edu/administration_cs/ir/factbook2008/upload/Admissions.pdf</a></p>
<p>Here are the data for 2007:</p>
<p>2007 SAT CR 25%-50%-75%: 640-690-720
2007 SAT M 25%-50%-75%: 640-680-720
so, by the USN method, simply adding the separate totals together for 25% and 75%, they’d get: 1280-1440 (which I believe they did, don’t have that USN edition in front of me)
but Colby reports this combined total:
2007 SAT M+CR 25%-50%-75%: 1310-1370-1430
…30 point closer (higher) to median on the low end, and 10 points closer (lower) on the high end.</p>
<p>Same story, different variances, for each other year reported.</p>
<p>I’d expect that schools that tend to admit applicants less balanced in SAT scores (higher score variation between one student’s M & CR score) would have larger variances between ‘real’ SAT M+CR quartiles compared to the USN additive method.</p>