How is mastery of a skill determined for a child in terms of accuracy and session frequency?

Determining mastery of a skill in children, particularly in the context of behavioral interventions and educational practices, typically requires a balance between accuracy and consistency over time. Option B reflects this balance effectively: achieving 80% accuracy over three consecutive sessions indicates a level of reliability in the child's performance that is deemed satisfactory for mastery.

This approach accounts for both the accuracy of task performance and the consistency of that performance across multiple sessions. Mastery isn't merely about achieving a high score once; it is essential that the child demonstrates this level of skill repeatedly in a stable manner, which is vital for generalization and application in various contexts. The three-session requirement allows for the observation of performance trends and recognizes that a child may perform differently on different days due to various factors.

Other choices lean too heavily on either a singular high performance or an extended number of sessions with lower accuracy, which may not provide a clear picture of mastery. Thus, the emphasis on 80% accuracy across three consecutive sessions in option B correctly encapsulates a more comprehensive evaluation of skill mastery.