Here's a link to either the study you're looking for, or a similar one: http://conservancy.umn.edu/bitstream/139295/1/2002%20NASSP%20Bulletin,%20Vol.%2086%20No.

Here's a link to either the study you're looking for, or a similar one: http://conservancy.umn.edu/bitstream/139295/1/2002%20NASSP%20Bulletin,%20Vol.%2086%20No.%20633.pdf http://conservancy.umn.edu/bitstream/139295/1/2002%20NASSP%2...