The past quarter of a century has seen wide extension of the use of schoolhouses for social, recreational, and community purposes, providing fuller utilization of school buildings erected usually at heavy cost. Thirty-two States have definitely provided by law for such use, and in the other States school authorities permit it under their general powers as custodians. Two previous bulletins recorded progress of this movement. This bulletin provides an overview and current appraisal of its development, including: (1) Types of "extended use"; (2) The definition of "school center"; (3) Scope of the investigation; (4) Distribution of school centers; (5) Length of season; (6) Evenings per week centers open; (7) Auspices; (8) Financial support; (9) The school center staff; (10) Activities; (11) Classes of groups meeting in school centers; and (12) Comparison with Perry survey [1919-1920]. (Contains 11 tables and 5 footnotes.) [Best copy available has been provided.]