Bill Turque’s recent article in the Washington Post (12-13-09) points out that under Michelle Rhee (but not previously), the gaps between white and black; between poor and non-poor; and between high-achievers and low-achievers among DCPS students have gotten noticeably larger. Please permit me to show how striking Rhee’s enlarged gap is, and to compare it to the rest of the country.
In fact, I conclude that the enlargement of this gap is Michelle Rhee’s singular achievement so far as Chancellor of the DC public school system, since she has so far not succeeded in breaking the Washington Teachers’ Union, which was probably her main goal, and since scores on the NAEP and DC-CAS were going up pretty steadily before she arrived.
First of all, let’s compare 4th grade students’ scores in DCPS in math on the NAEP, or National Assessment of Educational Progress, over the time period 2003 – 2009, for various percentile ranks. (Students at the 90th percentile do better than 90% of their fellow students, or cohort, so they are probably very good at math, compared to their DCPS peers. If you are at the 75th percentile, you do better than 75% of your cohort. And so on. Naturally, the students in the 25th percentile in 2003 are not the same students who were at the 25th percentile in 2009; however, both students were right in the middle of the bottom half of their class. The scores are whatever the scaled score was that they got on the NAEP. And no, I don’t quite know what that means either. But a higher score on the NAEP is most likely better than a lower score. It appears that NAEP scores can range from 0 to 500. All my data comes from the lengfthy PDF file on the NAEP TUDA report, which is at http://nationsreportcard.gov/math_2009/math_2009_tudareport/ .
Notice that although all of the groups’ scores are generally increasing, the scores for the students at the 75th and 90th percentiles are going up a lot faster during the last 2 years. So the gap between the top and bottom students is widening in the 4th grade in DC, under Michelle Rhee’s watch.
Rhee’s defenders will probably object that this is happening everywhere in the country. But that is not true. Here is a table and graph of the exact same percentile ranks for the nation as a whole:
To make this a bit clearer, I also have made a table showing the gaps between the 90th and 10th percentiles in the nation as a whole, in all large cities, and in DCPS. Take a look at how much it has grown in DC in the past few years:
Next, let’s look at the 8th grade. The story is very similar, but there are differences. In 2009, the students in DCPS at the 25th and 10th percentiles actually did worse than their counterparts in 2007. And the gap widened.
What about the nation as a whole? Much like in 4th grade:
Quite a disturbing pattern. Tomorrow: even more graphs and data, including the white-black gap and the poor-nonpoor gap!
Bill Turque’s article can be found at http://www.washingtonpost.com/wp-dyn/content/article/2009/12/12/AR2009121201276.html?nav=emailpage or http://tinyurl.com/turque12-13 .