Names of author(s)

Title

Language

Journal

Year

Country

Participant characteristic (age, grade level, gender, socioeconomic status, ethnicity)

Duration of class size reduction (years)

Class size (divide into treated/comparison)

Type of data used in study (administrative, questionnaire, other (specify))

Level of aggregation (individual or class)

Time period covered by analysis (divide into intervention and follow up)

Sample size (divide into treated/comparison)