Another pathetic attempt to explain away the black/white gap in academic achievement

Posted on May 12, 2009

An excerpt from another skeptic:

Today’s New York Times column by David Brooks touts a new study by Roland Fryer and Will Dobbie of the Harlem Children’s Zone (HCZ) Promise Academy charter schools, two celebrated schools in Harlem. Fryer and Dobbie’s finding that the typical eighth-grader was in the 74th percentile among New York City students in mathematics leads Brooks to state that HCZ Promise Academy eliminated the black-white achievement gap. He’s so dumbstruck by this that he says it twice. Brooks takes this evidence as support for the “no excuses” model of charter schools, and, claiming that “the approach works,” challenges all cities to adopt this “remedy for the achievement gap.”

Coming on the heels of yesterday’s release of the 2009 New York State English Language Arts (ELA) results, in which the HCZ schools outperformed the citywide white average in grade 3, but were well behind the white average in grades 4, 5 and 8, skoolboy decided to drink a bit more deeply from the datastream….

It’s true that eighth-graders in 2008 scored .20 standard deviations above the citywide average for white students. But it may also be apparent that this is a very unusual pattern relative to the other data represented in this figure, all of which show continuing and sizeable advantages for white students in New York City over HCZ students. The fact that HCZ seventh-graders in 2008 were only .3 standard deviations behind white students citywide in math is a real accomplishment, and represents a shrinkage of the gap of .42 standard deviations for these students in the preceding year. However, Fryer and Dobbie, and Brooks in turn, are putting an awful lot of faith in a single data point — the remarkable increase in math scores between seventh and eighth grade for the students at HCZ who entered sixth grade in 2006. If what HCZ is doing can routinely produce a .67 standard deviation shift in math test scores in the eighth grade, that would be great. But we’re certainly not seeing an effect of that magnitude in the seventh grade. And, of course, none of this speaks to the continuing large gaps in English performance.

But here’s the kicker. In the HCZ Annual Report for the 2007-08 school year submitted to the State Education Department, data are presented on not just the state ELA and math assessments, but also the Iowa Test of Basic Skills. Those eighth-graders who kicked ass on the state math test? They didn’t do so well on the low-stakes Iowa Tests. Curiously, only 2 of the 77 eighth-graders were absent on the ITBS reading test day in June, 2008, but 20 of these 77 were absent for the ITBS math test. For the 57 students who did take the ITBS math test, HCZ reported an average Normal Curve Equivalent (NCE) score of 41, which failed to meet the school’s objective of an average NCE of 50 for a cohort of students who have completed at least two consecutive years at HCZ Promise Academy. In fact, this same cohort had a slightly higher average NCE of 42 in June, 2007.

So what we have is a truly laughable attempt to generalize from a single aberrant instance. The first thing you learn in Statistics 101 is that you CANNOT generalize from a single instance. That the unusual result was “fudged” in some way would be the most rational conclusion. Teachers “helping” students do tests in various ways is reported from time to time.

Posted by John Ray. For a daily critique of Leftist activities, see DISSECTING LEFTISM. To keep up with attacks on free speech see TONGUE-TIED. Also, don’t forget your daily roundup of pro-environment but anti-Greenie news and commentary at GREENIE WATCH . Email me (John Ray) here

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