Learning conditions that provide task-relevant autonomy, and those that encourage cognitive
effort through manipulations of difficulty, have been reported to enhance skill development.
However, research is yet to directly compare these two manipulations to establish their relative
contribution to enhancing motor learning. This study used an on-screen target interception task to compare an autonomous group (self-selection of racquet size), a Challenge Point group (performance-contingent racquet size), a yoked group, and a fixed racquet size control group. Task accuracy and self-report measures of intrinsic motivation and cognitive effort were recorded at multiple time points across acquisition and at immediate, 24-h, seven-day, and 30-day retention and transfer tests. Results showed that task accuracy improved over acquisition, and remained robust across all retention tests, but no between group differences were seen. Intrinsic motivation levels decreased over acquisition, but with no between group differences observed. Participants (83, mean age 40(±12) years, 50 % male) within all groups reported consistently high cognitive effort scores, and made tactical learning choices, suggesting that high task difficulty may have suppressed the more subtle effects of autonomy and performance contingent practice. Conclusions are made regarding the variability of individual approaches to a novel task and the need to build experiments that can detect these idiosyncrasies.