More on that awful Gates study

Though science does sometimes prove things that are not intuitive, science does depend on accurate premises. So, in this case, IF the conclusion is that “you can’t believe your eyes” in teacher evaluation — just because you watch a teacher doing a great job, this could be a mirage since that teacher doesn’t necessarily get the same ‘gains’ as the other teacher that you thought was terrible based on your observation — well, it could also mean that one of the initial premises was incorrect. To me, the initial premise that has caused this counter-intuitive conclusion is that value-added — which says that teacher quality can be determined by comparing student test scores to what a computer would predict those same students would have gotten with an ‘average’ teacher — is the faulty premise. Would we accept it if a new computer programmed to evaluate music told us that The Beatles’ ‘Yesterday’ is a bad song?

One thing that struck me right away with this report is that the inclusion of student surveys — something that aren’t realistically ever going to be a significant part of high stakes teacher evaluations — is given such a large percentage in each of the three main weightings they consider (these three scenarios are, for test scores-classroom observations-student surveys, 50-25-25, 33-33-33, and 25-50-25.)

Conspicuously missing from the various weighting schemes they compare is one with 100% classroom observations. As this is what many districts currently do and since this report is supposed to guide those who are designing new systems, wouldn’t it be scientifically necessary to include the existing system as the ‘control’ group? As implementing a change is a costly and difficult process, shouldn’t we know what we could expect to gain over the already existing system?

[readon2 url="http://garyrubinstein.teachforus.org/2013/01/13/50-million-3-years-no-clue/"]Read the whole piece[/readon2]