Blooms Sigma 2 Problem
In the June July Edition of Educational Researcher, Volume 13, No. 6, Bloom published the findings research by two of his doctoral students. This research compared student learning under the following conditions of instruction.
The comparison of three conditions of instruction:-
Conventional (Lecture). Students learn the subject matter in a class with 30 students per teacher. Test are given periodically.
Mastery. Students learn the subject matter in a class with 30 students per teacher. Instruction is the same as Conventional class. Formative test are given (same as Conventional), given feedback followed by correctional procedures and parallel formative tests to determine extent to which students have mastered the subject matter.
Tutoring. Students learn the subject matter with a good tutor for each student (upto 2 or 3 simultaneously). This tutoring is followed by formative tests, feedback-corrective procedures, and parallel formative tests .
Instructional treatment was limited to 11 periods of instruction over 3 weeks block time.
Most Striking were differences in achievement measures under the three conditions.
Using the Standard Deviation (sigma) of the control (conventional class), it was typically found that the average student under tutoring was about 2 standard deviations above the control class.
The average tutored student was above 98% of the students in the control.
Average student under mastery learning was about one standard deviation above the average of the control class, the average mastery student was above 84% of the students in the control.
Most striking of the findings is that under the best learning conditions we can devise(tutoring), the average student is 2 sigma above the average control student taught under conventional groups.