Criteria for Evaluation Studies Included in LINKS

Since the purpose of LINKS is to compile a compendium of social interventions for children, we have attempted to be as inclusive as possible. In selecting programs for LINKS, 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[1] 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%, 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:

a)     utilize teaching methods appropriate for out-of-school time programs (e.g., educational television programming or computer software);

b)     are conducted with preschool children in daycare or in other preschool programs;

c)     involve volunteer tutors; or

d)     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.