Why did charter scores fall more?
AUGUST 10, 2013 PM31 1:50 PM
Stephen Krashen warned (in advance, in a letter to the NYDN):
…Robert Linn of the University of Colorado and his colleagues have shown that test scores are typically low when a new test is introduced. Then the scores improve, about one to two points a year, as students and teachers get more familiar with the test. This is not because of brave new “rigorous” curricula; the improvements stop after a few years, after students and teachers have adapted to the new measures.
Gary Rubinstein looked at NYC charter school scores, and noticed (and made a convincing-style chart):
…As can be clearly seen, the charters are, in general, the ‘outliers’ meaning the schools that had the biggest drops relative to other schools with similar 2012 scores.
The simplest explanation is often the best. Charters fell further, because they had risen further. Which fits with the common observation that many charters in NYC are fairly effective test prep