Cross-country gender DIF in PISA science literacy items

This study investigated gender based differential item functioning (DIF) in science literacy items included in the Program for International Student Assessment (PISA) 2012. Prior research has suggested presence of such DIF in large scale surveys. Our study extends the empirical literature by examining gender based DIF differences at the country level in order to gain a better overall picture of how cultural and national differences affect occurrence of uniform and nonuniform DIF. Our statistical results indicate existence of widespread gender based DIF in PISA with estimates of percentage of potentially biased items ranging between 2 and 44% (M = 16, SD = 9.9). Our reliance on nationally representative country samples allow these findings to have wide applicability.