( CNN ) -- The debate over teacher evaluations that 's taken center stage in the Chicago schools strike could have major effects on the issue in the future , an education expert says . `` Chicago absolutely matters , '' said Elena Silva , senior associate for public policy engagement at the Carnegie Foundation for the Advancement of Teaching . `` I think what happens here will substantially matter for what we see happen with teacher evaluations nationwide , '' she said . In the last three years , 21 states have passed have legislation or implemented new regulations designed to highlight teacher accountability , according to a report by Bellwether Education Partners , a consulting firm . The changes came often by way of the kind of standardized testing that one Chicago Teachers Union board member referred to as `` data-driven madness . '' My View : A parent 's take on the CPS teachers strike . In many -- but not all -- cases , the reforms were hotly contested , with teachers unions saying the changes put jobs at risk without enough evidence they would work in the way both sides say reforms should work -- helping students learn , said Sara Mead , a Bellwether analyst who tracks teacher effectiveness policy nationwide . `` In a lot of places , this has been fairly controversial , but that has not been universal , '' she said . For instance , in New York , teachers unions sued over a 2010 law implementing teacher effectiveness standards in return for funding under President Barack Obama 's Race to the Top initiative . But in Colorado , unions and state officials worked together on a law that calls for incentive pay based on performance , according to Mead . Similar issues have arisen elsewhere . In Boston , negotiations on a new contract stalled for a while , in part over differences in teacher evaluations . In 2009 , then-Washington schools Superintendent Michelle Rhee ignited a firestorm with a teacher evaluation model that put heavy emphasis on standardized test scores . At the time , the president of the Washington Teachers Union called the evaluation standard a `` flawed instrument with many loopholes . '' Many of the state changes were part of what Mead 's Bellwether report referred to as an `` unprecedented wave of legislation , '' much of which could be traced back to the $ 4.25 billion Race to the Top program . The 2009 initiative offers states money under a competitive grant program in return for adopting teacher effectiveness standards and a host of other reforms . It 's been an attractive proposition to reform advocates and to many cash-strapped state governors and legislatures -- do something to make teachers more accountable , among other things , and we 'll give you more money , Silva said . And unions have moved on the issue of accepting updated evaluation standards , dropping wholesale opposition for nuanced support . Voices of the strike . Last year in Chicago , for instance , delegates to the National Education Association 's annual conference approved a new policy statement that calls for `` robust evaluations by highly qualified evaluators using multiple indicators , not a single narrow metric . '' But those same unions have hotly contested such changes , arguing that making high-stakes decisions about teaching jobs should n't flow from the results of standardized test scores alone . `` Unions do n't want teachers being evaluated on student achievement because , the strongest argument or the most common one is , there are too many factors outside control of teachers , '' Silva said . In Boston , where the teachers union has been fighting with city officials over evaluations , union officials wrote on their website that the Race to the Top money `` will dry up shortly , leaving bad policy in its wake . We can not afford to give up our fight to restore some common sense to what have been mislabeled reforms . '' Key issues in the strike . But the drumbeat for change is unlikely to abate , Silva said . `` There is a clear sign that teacher evaluation is changing and will change , '' she said . `` Where it will go and what it will look like is still up for grabs . '' Teachers : Why do you teach ?
After Race to the Top initiative , fights over teacher responsibility have become more common . Comment: The Chicago schools strike could influence the outcome of the debate , expert says .