Thursday, August 03, 2006

Public v. Private Round ... 100?

The Program on Education Policy and Governance at Harvard has released a new report fueling the discourse between online and hard line supporters of private schools and public schools. The confrontational Harvard study by Peterson and Llaudet acknowledges the ETS/NCES study released July 14, 2006 then knocks it down. "NCES's measures of student characteristics are flawed by inconsistent classification across the public and private sectors and by the inclusion of factors open to school influence." It appears Peterson and Llaudet has worked fast and into the wee night hours to rejoin ETS/NCES's work and demonstrate contrary results.

Peterson and Llaudet come up with three alternative models of reclassification of variables. Basically they didn't like the proxy constructs NCES used to measure affluence and poverty, so they came up with their own. Alternatives three:

Peterson and Llaudet didn't like NCES's Title I and Free Lunch variables since Title I funding is used by only 19 percent of private schools versus 54 percent of public schools. Instead Peterson and Llaudet's first model, Model I, substitutes the Title I and free Lunch variables for parents' education and the location of the school (regionally and by urban or rural area) . Model II eliminates NCES's use of the LEP and IEP variables, replacing them with other variables based on student reports of the frequency with which a language other than English is spoken at home. Finally, Model III, eliminates NCES's absenteeism, computer, and books in the home variables, thereby, according to Peterson and Llaudet, avoiding the inclusion of student characteristics that can be influenced by the school. This is all a way of trying to prove a bias NCES's report that "under-counted the incidence of disadvantage in the private sector and over-counted its incidence in the public sector."

The part about all of this that makes me laugh are the constant disclaimers about moment in time effects that lack reliability without longitudinal data. Peterson and Llaudet at ondenounceuce NCES's use of the NAEP data sbecausesue NAEP never measures individual student achievement over time, yet the data are not their biggest gripe. Inconsistent and potentially confounded variables are their gripe. But come on, the headlines are big and neon and glowing: Harvard says privates do better. Well, Harvard also suggests that poor kids go to private schools too. Some do, but I don't need any data to tell me that a whole lot more poor kids go to public schools.

Really all Peterson and Llaudet have done is introduce to the rest of us, who generally already understand, that when it comes to schools and people, we don't have all that many reliable indicators. Thank God we can't be reduced to a simple set of characteristics. The debate rages. Touche Crimson and White. Touche.


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