Many school districts in state don't comply with teacher evaluation law 

[Los Angeles Times, 1/21/15]

Major California school districts are failing to comply with a state law that requires them to evaluate teachers in part by how much their students have learned, according to a study released Wednesday.

http://www.latimes.com/local/education/la-me-school-evaluations-20150121-story.html

Does Better Observation Make Better Teachers? [Education Next, Jan. 2015]:

New evidence from Chicago is discussed

http://educationnext.org/better-observation-make-better-teachers/

But see However, see a counterpoint post at “Crumudgucation”:

http://curmudgucation.blogspot.com/2015/01/poverty-matters-ep-2364339.html?m=1