What type of practice involves little or no rest between repeat performances of a skill?

Massed practice is characterized by sessions where learners engage in repeated performances of a skill with minimal or no rest intervals between repetitions. This approach is often used when the skill is relatively simple or in a controlled environment where the aim is to increase the number of practice repetitions in a limited time. The lack of rest can lead to fatigue which causes the learner to focus intensely on the task at hand. This can accelerate skill acquisition but may also lead to decreased performance quality, particularly in more complex or physically demanding skills.

In contrast, distributed practice features longer rest periods between repetitions, allowing for recovery and potentially better retention of skills. Task constraints involve modifying the environment or rules of the task to facilitate learning, and core learning does not specifically define a practice strategy related to rest intervals. Therefore, massed practice is clearly defined by its nature of minimal rest, making it the correct answer in this context.