Practical Significance in Special Education Research

Abstract

Whereas statistical significance indicates whether a difference is a difference, additional information signifying whether the difference is large enough to make the results worth acting upon is included in practical significance. Statistical measures of practical significance report the extent to which variation in the dependent variable can be explained by the independent variable. Measures of practical significance are seldom reported in The Journal of Special Education, although sometimes issues of practicality are discussed using the estimate of statistical significance. Practical significance, however, may vary greatly among samples even though statistical significance estimates are similar.