
The Search for Methods of Group Instruction as Effective as Tutoring (1984) [pdf] - joaorico
http://web.mit.edu/5.95/readings/bloom-two-sigma.pdf
======
joaorico
Also:
[https://en.wikipedia.org/wiki/Bloom%27s_2_Sigma_Problem](https://en.wikipedia.org/wiki/Bloom%27s_2_Sigma_Problem)

