The 2 Sigma Problem: The Search for Methods of Group Instruction as Effective as One-to-One Tutoring

Bloom, B. S. (1984)

Zitation (APA)

Bloom, B. S. (1984). The 2 Sigma Problem: The Search for Methods of Group Instruction as Effective as One-to-One Tutoring. Educational Researcher, 13(6), 4-16. http://dx.doi.org/10.3102/0013189X013006004