An appropriate estimate of statistical power is critical for the design of intervention studies. Although the inclusion of a pretest covariate in the test of the primary outcome can increase statistical power, samples selected on the basis of pretest performance may demonstrate range restriction on the selection measure and other correlated…

The American public school curriculum has narrowed as a result of the No Child Left Behind Act of 2001. Music is being eliminated in public schools so more time and resources can be spent on "tested" subjects like reading and math. However, research has shown that both the intrinsic and extrinsic values of music may improve reading…