The 2 Sigma Problem

In 1984, Benjamin Bloom identified a learning dilemma he dubbed the “2 Sigma Problem”–tutored students perform two standard deviations better than students who learn via conventional methods. Noting that one-to-one tutoring is “too costly for most societies to bear on a large scale,” Bloom challenged researchers and teachers to “devise teaching-learning conditions that will enable the majority of students under group instruction to attain levels of achievement that can at present be reached only under good tutoring conditions.” The purpose of this seminar will be to reexamine Bloom’s dilemma and challenge after a quarter Century of intervening innovation and research. Beginning with Bloom’s 1984 article, the class will conduct a meta-analysis of the student performance literature. The class product will be a multi-authored article aimed at answering these questions: (1) Are we any closer to closing the 2 sigma gap? (2) If not why? (3) How cam researchers and teachers facilitate broadly realized levels of achievement on par with those realized via one-to-one instruction?