---

  Dr. Bloom to summarize the 2 Sigma problem

---

“ The tutoring process demonstrates that most of the students have the potential to reach this high level of learning.  I believe an important task of research and instruction is to seek ways of accomplishing this under more practical and realistic conditions than the one-to-one tutoring, which is too costly for most societies to bear on a large scale.  This is the “2 sigma” problem.  Can researchers and teachers 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? ”
A Paper was published in 1984 by Benjamin Bloom based on work done by his doctoral students  (Joanne Anania and Arthur Burke)

The experiment was done multiple times in two subject areas and with students in grades 4, 5, and 8 Over a 3-week period, students were randomly assigned to one of these three groups

Conventional:
30 students in a class are taught the subject matter by a teacher; students are given periodic tests.

Mastery Learning:
Same as Conventional, but with additional formative assessments and feedback to determine the extent to which students have mastered the topic.

Tutoring:
Groups of 1-3 students are taught by a tutor over the 3-week period and given the same assessments as the Mastery Learning group.

The difference final achievement measures was significant:

The average Mastery student scored higher than 84% of the Conventional students (this is a 1 Sigma or one standard deviation improvement)

The average Tutored student scored higher than 98% of the Conventional students (this is the 2 Sigma improvement from the title)

---

---