Partial correlation coefficients are often used as effect sizes in the meta-analysis and systematic review of multiple regression analysis research results. There are two well-known formulas for the variance and thereby for the standard error (SE) of partial correlation coefficients (PCC). One is considered the "correct" variance in the…

An aspect of the complex relationship between students homework and academic achievement (Cooper, Robinson, and Patall, 2006) was examined by correlating TIMSS 2003 mathematics results with the data about homework in 46 countries of the TIMSS study. The TIMSS results had no statistically significant correlation with the teachers' emphasis on…