The authors looked at the work cited in the 2010 LA Times release of value-added scores for LAUSD teachers. The review disputes the finding that teacher qualifications have no association with student outcomes, looks at the issue of non-random assignment , and discusses the (im)precision of the model used.
The authors conclude:
Causal inference may well be the holy grail of quantitative research in the social sciences, but it should not be proclaimed lightly.When the causal language of teacher "effects" or "effectiveness" is casually applied to the estimates from a value-added model simply because it conditions on a prior year test score, it trivializes the entire enterprise. And instead of promoting discussion among parents, teachers and school administrators about what students are and are not learning in their classrooms, it seems much more likely to shut them down.You can read the full research report here.
Remarkably, the LA Times' Jason Felch read this review and concluded that it confirmed much of the previous analysis. His story ran with the headline (chosen by either Felch or an editor) "Separate study confirms many Los Angeles Times findings on teacher effectiveness." A fact sheet later published by NEPC notes the Times also broke the embargo, a move that reflects poorly on the newspaper. Briggs and the Times assistant managing editor both appeared on 89.1 KPCC to explain their work, the latter sounding more like an advocate/PR man than an editor.