We tested hypotheses about the respective roles of working memory, perceptu
al speed, knowledge, and attention disengagement processes in skill transfe
r errors that resemble einstellung effects or strong-but-wrong slips. Corre
lational evidence was consistent with the hypothesis that these errors are
primarily due to the inability of learners to disengage attention from expe
cted or familiar operations. The data also supported the notion that error
proneness during near transfer generalizes across different skills. Contrar
y to expectations, working memory capacity had little or no relationship to
either transfer errors or attention disengagement ability. Results are dis
cussed with respect to skill training and individual differences in skill p
erformance ability. (C) 2001 Elsevier Science Inc. All rights reserved.