Table 1.

Performance measures

Measure	Summary
Mastery speed	The total number of problems completed before students achieve mastery (Xiong et al. 2013; Xiong et al. 2014). In the ASSISTments’ Skill Builder assignment, mastery is defined as accurately answering three consecutive problems. When a student achieves mastery, they are no longer assigned more problems in that Skill Builder. In the current study, students used anywhere from 3–40 problems to master the Skill Builder, with an average of 8 problems.
Percent correct	The number of problems answered correctly out of the total number of problems attempted. Compared to the mastery speed measure, percent correct is more susceptible to guessing and provides less penalty to slipping because correct answers are credited even though prior or future problems are answered incorrectly. Baker et al. (2008) define guessing as providing the correct answer despite not knowing the skill and slipping as providing an incorrect answer despite knowing the skill.
Total answer-attempts	The total number of answer attempts students made while solving problems in the Skill Builder. Take note that this is different from the number of problems answered in the mastery speed measure. Low total answer-attempt counts may indicate that the student has sufficient knowledge to answer problems, while high answer-attempt counts may indicate difficulty with the problem or possibly engagement in systematic guessing or gaming behavior (Baker et al. 2004).
Total regular-hint count	The total number of hints requested by students throughout the Skill Builder that did not reveal the correct answer (i.e., non-bottom-out hint).
Total bottom-out-hint count	The total number of bottom-out hints requested by students while solving the Skill Builder.
Problems with hints	The number of problems in the Skill Builder in which the student requested either regular or bottom-out hints.
Attrition	The case when a student failed to complete the problem set, or effectively “dropping out” of the Skill Builder.