Transforming response time and errors to address tradeoffs in complex measures of processing speed

•We evaluated four response time metrics for adjusting speed–accuracy tradeoffs.•The optimal transformation was a response rate adjusted for errors (RRAdj).•RRAdj equated scores whether participants emphasized speed or accuracy.•As a reciprocal of response time, RRAdj reduced distribution skewness.•RRAdj accounted for more variance in criterion measures than response time.

An experiment evaluated a transformation of response time (RT) into response rate adjusted for errors (RRAdj) for its ability to accommodate different speed–accuracy tradeoffs (SATs). Participants solved 2-step arithmetic problems under instructional conditions that emphasized speed versus accuracy of responding. RT and error variables were transformed using RRAdj and three additional computations to determine which better equated performance scores under the two tradeoff conditions. Effective adjustment for SAT strategy was evaluated by the equivalence of predictive relationships with other variables, regardless of SAT instructional set. Of the scoring computations compared, RRAdj alone equated performance in the tradeoff conditions, and it was optimized when accuracy was adjusted for guessing. Thus, in certain multistep cognitive tasks, incorporating RT and error data in the RRAdj computation could at least partially adjust for differing SAT strategies and embody additional meaningful variance compared to the commonly used RT for correct responses.