Tullis, J. G., Goldstone, R. L., & Hanson, A. J. (2015).  The extent and arrangement of assistance during training impacts test performance.  Journal of Motor Behavior, 5, 442-452.

Various kinds of assistance, including prompts, worked examples, direct instruction, and modeling, are widely provided to learners across educational and training programs.  Yet, the effectiveness of assistance during training on long-term learning is widely debated.  In the current experiment, we examined how the extent and schedule of assistance during training on a novel mouse movement task impacted unassisted test performance.  Learners received different schedules of assistance during training, including constant assistance, no assistance, probabilistic assistance, alternating assistance, and faded assistance.  Constant assistance led to better performance during training than no assistance.  However, constant assistance during training resulted in the worst unassisted test performance.  Faded assistance during training resulted in the best test performance.  This suggests that fading may allow learners to create an internal model of the assistance without depending upon the assistance in a manner that impedes successful transfer to unassisted circumstances.