Exposure to Instruction,Surplus Time,and Student Achievement: A Local Replication of the Harnischfeger and Wiley Research1

Abstract

This study reports the results of what the authors term a "local replication" of Harnischfeger and Wiley's research concerning the effects of exposure to schooling on student achievement. Data were collected which covered a ten-year period surrounding a high school's deliberate reduction of the amount of classroom time available to its students. Both a time series analysis and a regression analysis suggest that the reduction affected mathematics but not English achievement. The utility of local replications for both practitioners and researchers is discussed.