This study examines the relative effects of motivational orientation, ability, social class, sex, and instructions to employ verbal mediation on a paired-associates (PA) learning task. One hundred ninety-two seventh and eighth grade students were categorized according to degree of Intrinsic Task Motivation (IM), ability, and social class (SES). The experimental variable was the presence or absence of instructions to form a verbal mediation between PA elements (nouns). A significant four-factor interaction (IM x Sex x Ability x Trials) was found along with one significant three-factor interaction and several two-factor interactions. There were significant main effects for Sex, Ability, and Trials. Simpler analyses were performed separately for boys and girls, each yielding significant three-factor interactions (IM x Ability x Trials). Additional subanalyses indicated that IM and Ability interact in a complex and different manner for boys and girls. Girls made fewer errors than boys, and high ability subjects made fewer errors than low ability subjects. (Author)