Tuesday, June 02, 2009

TAKS Improvements

Lies, damned lies, and statistics

Jeffrey Weiss, in The Dallas Morning News Richardson blog, reports the good news that the Richardson ISD "has reduced the gap in scores since 2005 between white students and those of blacks, and Hispanics. Bottom line: On every test, the gap has shrunk. In some cases pretty dramatically."

It's good news as far as it goes. But, as the saying popularized by Mark Twain goes, "There are three kinds of lies: lies, damned lies, and statistics." And someone really needs to explain the limitations of the TAKS scores in giving a complete picture of what's going on in our schools. I'm not sure administrators themselves understand just how limited their statistic of record is.

That's because TAKS scores only measure how many students get over a very low bar, not by how far they get over it. Both groups can approach 100% success without the gap in absolute achievement closing at all. It's possible for whites to clear the bar by ever higher and higher margins while blacks are only just getting over. I'm not saying this is what's happening. I'm saying the current TAKS measurement doesn't tell us enough about what's really going on in our schools.

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