Though individual schools and districts often boast about improved student performance and attendance after choosing to require uniforms, a comprehensive study of national data published in "Educational Policy" found no direct link between uniforms and student achievement. In some instances, the study found the opposite effect. It's possible that faculty wish to perceive students as sharper and more disciplined because of the uniforms, but on a national scale, the uniforms prove to be only a superficial fix to other serious problems. Anecdotal evidence of improved results in a school with mandatory uniforms may be because the school has begun enforcing the rules more seriously, and may have nothing to do with the uniforms at all.