Tuesday, December 18, 2012

Bias in Texas Growth Measure and Implications for Austin and IDEA Charter « A "Fuller" Look at Education Issues

Bias in Texas Growth Measure and Implications for Austin and IDEA Charter « A "Fuller" Look at Education Issues:


Bias in Texas Growth Measure and Implications for Austin and IDEA Charter

One of the often over-looked factors that influence achievement are peer effects. There is a growing body of literature that concludes peer effects have fairly substantial effects on individual achievement. However, it is incredibly difficult to disentangle peer effects from all the other factors influencing student achievement. (1) The preponderance of the research is pretty clear in this area–students placed in classrooms with peers with greater achievement will likely benefit from positive peer effects while those placed in classrooms with students of lower achievement will likely suffer from negative peer effects. Moreover, lower performing students benefit more from positive peer effects than other students while higher performing students suffer more from negative peer effects than other students.
This plays out in assessments of teachers and schools when judgments are made without controlling for the incoming ability of students. And, even when incoming ability is controlled for in the statistical analysis, peer effects are often so difficult to capture in a statistical model that the results end up being biased with respect to incoming ability. Bias simply means that the end result of the analysis is still associated with some characteristic of the teacher or school not under the control of the teacher or school personnel. For a great