This is the protocol for a Campbell systematic review. The review will address the following research questions: What is the evidence on the effects of adult mentoring programmes in reducing anti-social, violent and offending behaviour in children aged under 18 years? Are these effects sustained after the end of mentoring? Which aspects/features of adult mentoring programmes promote the reduction of anti-social, violent and criminal behaviour in children aged under 18 years? What are the hindering factors/barriers that affect the successful implementation of adult mentoring programmes in children aged under 18 years? What are the supporting factors/facilitators that contribute to the successful implementation of adult mentoring programmes in children aged under 18 years? What is the evidence on programme costs and incremental cost effectiveness? (The incremental (or marginal cost) is the cost of providing the intervention over and above the cost of usual services).

This review will synthesize the results from publications focused on homework time and academic performance, and estimate the relationship between the two. Our objectives are: (1) To identify the extent of the relationship between homework time and students' academic performance; (2) To analyze the differences in the effectiveness of homework time across genders, grades, subject and regions; and (3) To identify the potential factors that affect homework time, such as academic subject, task difficulty, type of homework, mode of homework, parental involvement, and feedback on homework.