The use of a proficiency index or providing schools credit for students at different points in the achievement distribution improves the construct
validity of the accountability measures over the NCLB proficiency rate measures (Polikoff et al., 2014).
In addition, since these assessments are self - report surveys, there is also the issue
of response bias — meaning a student's tendency to give answers that they believe are socially acceptable or to consistently answer «yes» or «no» regardless
of the question asked.48 Since self - report
measures tend to be weak in reliability and
validity, state and local policymakers should refrain from including
measures of learning mindsets and skills in high - stakes
accountability systems.