Eligibility Criteria

To submit an evaluation for consideration, email whatworks@childtrends.org.

General Eligibility Criteria for Child Trends’ What Works Analyses

Since the purpose of What Works is to compile a database of social interventions for children, we have attempted to be as inclusive as possible. In selecting programs for this database, we have used the following criteria:

  • Only social interventions (that is, not medical) are included.
  • Every study has a treatment group and a control group, and random assignment (that is, a lottery system) was used to determine placement of participants into treatment and control groups.
  • Only results based on an intent-to-treat analysis are reported.
  • Studies were conducted around the world, but all reports are in English.
  • Studies are included if they have a response rate as low as 50 percent, but evaluations with low response rates and other major methodological limitations are noted.
  • Results meeting the .05 level of significance were reported.
  • Classroom-based programs are included if they:
    • utilize teaching methods appropriate for out-of-school-time programs (e.g., educational television programming or computer software);
    • are conducted with preschool children in daycare or in other preschool programs;
    • involve volunteer tutors; or
    • are held during the summer months, when school is not in session.
  • No restrictions were made on sample size.
  • No statistical re-analyses have been done to adjust or revise the results presented by the studies’ authors.

Special Eligibility Criteria for Analysis

Out-of-School Time Program Evaluation Criteria

  • Subjects are assigned to treatment and control groups through random assignment and are not re-assigned.
  • Results are based on intent-to-treat analyses including data for all subjects who were randomly assigned in the analysis, regardless of their participation in the study)
  • Interventions must be non-biomedical.
  • Classroom-based curriculum interventions are only included if they include methods appropriate for out-of-school-time programs, preschool children, or volunteer tutors/mentors, or are held while school is not in session.
  • Response rate must be at least 50 percent at post-test.