Strike Highlights Division on Teacher Evaluation One of the key disagreements driving Chicago teachers to the picket lines this week is also a central component of President Barack Obama's education policy: evaluating instructors in part on how much their students improve. Through its $4 billion Race to the Top competition and No Child Left Behind waivers, the Obama administration has encouraged states to change how teachers are assessed and include data on student growth as a component. That policy has hit a nerve in the education community, and not just among the unions. Critics note there is little if any evidence basing evaluations on test scores will improve student achievement and argue it is being implemented at a large scale too quickly. Those in support of the revamped evaluations argue that far too many teachers are retained and given above-average reviews without any real assessment. The dispute has now reached Obama's hometown and some say it could have an impact on get-out-the vote efforts for him in November. While both of the nation's largest teacher unions endorsed him, teachers could ultimately become hesitant to get family and friends to vote for him. "What really matters is whether teachers are going to be active in October and early November knocking on doors, manning the phone banks," said Mike Petrilli, executive vice president of the Thomas B. Fordham Institute, an education think tank. The Chicago Teachers Union argues the new evaluation system being put into place in the city is unfair because it relies too heavily on students' standardized test scores and doesn't take into account external factors like poverty, violence and homelessness that affect performance. They estimate 6,000 teachers could lose their jobs within two years as a result of the evaluations. City officials contend the union hasn't explained how it arrived at that figure. Mayor Rahm Emanuel, Obama's former chief of staff, said the evaluation would not count the first year as any kinks in the process are worked out. Second grade Chicago teacher Krystal Brown said one of the biggest issues for her in the negotiations was evaluations. She said oftentimes, students land in her classroom one to two grade levels behind and even if they improve by a year, her evaluation would only show they didn't meet grade level. Students in her South Side classroom deal with hunger, poverty and learning disabilities, and her classroom has just two working computers. "You can be doing everything - coming in early, staying late, going to their parents' house - but there are other factors," she said. Driving the change in policy is a state law passed in 2010 requiring all schools in Illinois to change how teachers and principals are evaluated and include student achievement as a component in that process by the 2016-17 school year. In the case of Chicago Public Schools, however, the timeline was moved up to September of this year for 300 schools. Illinois isn't alone in considering changes to evaluations; legislatures and districts all over the country have been grappling with the issue. Tim Knowles, director of the University of Chicago Urban Education Institute, said the prospect of receiving of hundreds of millions of dollars in federal funding through Race to the Top drove Illinois' state legislature to pass the law unanimously. The state was ultimately granted nearly $43 million in the competition.