Twelve pupils from each of thirteen middle school science classes participated in the study. Measures were obtained for each pupil on nine engagement modes. Two engagement measures, attending and generalizing, together with formal reasoning ability, were related to process skill achievement and retention. Formal reasoning ability was the strongest predictor of process skill achievement and retention, accounting for approximately 36% of the variance in each case. Formal reasoning ability and locus of control were each correlated with specific engagement modes. Formal reasoning ability was positively related with rates of generalizing and comprehending. Locus of control was significantly related with rates of attending and total engagement.