2 Sigma Problem

The 2 Sigma Problem in Education: A Revelation (1)

The 2 Sigma Problem

A man named Benjamin Bloom made an outstanding discovery in improving the academic performance of students in school. He found out that most students do not do well in school because they are sidelined unintentionally by the teacher in the traditional education. He noted that having one teacher to 20 students+ is an incredible difficult job and as such, it is practically impossible for a teacher to meet all of the demands of each of the students all at once considering that each class is timed based and the students are different individuals with varying ability to assimilate and also to pay attention.

Bloom’s research revealed that if mastery learning is introduced into the classroom, there will be a significant improvement in the performance of the student. This means that mastery learning is one standard above traditional learning. Mastery learning according to Bloom is getting a student to master a topic before moving to the next topic. This would involve a series of testing. It also gives the teacher the opportunity to focus on students that need the most attention as against traditional learning where the teacher shares their attention to the students

Bloom took his research a step further to discover what he termed one-to-one learning. Here, it is a teacher to one student. One-to-one learning is a combination of mastery learning and personalized learning. The research revealed that one-to-one learning is one standard deviation above mastery learning and two standard deviations above traditional learning. This discovery was what led to the 2 sigma problem.

The highlight of this discovery is that average students performance increased to 98% when taught one-to-one using mastery learning and personalized learning. This pointed my attention to very important points:

  1. The system is designed to keep us a average students
  2. There is no student that is not capable of mastery

It became increasingly important to provide this solution at scale


The 2 sigma problem has plagued the educational system for many years. Even after the discovery by Bloom about 37 years ago, there wasn’t a straightforward answer as to how to scale this solution – one-to-one learning. This discovery led to the question of cost and time. Cost in the sense that it is ridiculously expensive to give each child their own teacher. Time in the sense that it is time demanding to use personalized learning and mastery learning as the teaching methodology. 

Technology has however proven to be the messiah to providing the solution at scale. We have seen how technology has disrupted industries like the media & communication only to make every one a media company. Before now, we relied on traditional media like TV, Radio, Newspaper to know what is happening around the world. Today, with the click of a button, we can find out what is happening hundreds of countries away from us. Also, before, we had to wait for weeks to communicate with someone far away from us but today, we can communicate with just anyone in any part of the world. All thanks to technology.

The same has been made possible in education as we have seen platforms like Udemy, Cousera, create an educational library for people who want to learn whatever at their convenience. We have seen companies like BYJU, uLesson, etc. decentralize the learning process by giving children the power to control their learning and also master each topic before moving to the next.

As beautiful as the fusion of education with technology is, there seems to be quite some gray areas that need clarifications. Some includes:

  1. Will technology replace schools?
  2. Will technology amplify the problems plaguing education rather than provide solution
  3. If technology replaces schools, where would students learn to interact socially

These and more are questions we would be probing into in subsequent posts. While there is no doubt that technology will disrupt the educational system, history has taught us to be ready for anything – both good and bad. It is therefore of necessities to look beyond the immediate solution and dig into the different possibilities that might take shape in the nearest future and be prepared for them.

Hang with me as we look for answers together.

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  1. It’s good to learn that:
    “Technology is bridging the gap between traditional learning, mastery learning, and one to one learning.”

    I will hang with you as we look for answers together.

  2. I’m looking forward to the answers to the gray areas. Because as much as technology is good we can’t neglect the place of schools in shaping the social interaction of students which technology can not replace. I believe there will be a rendezvous going forward.
    Also, the one to one learning has been saving lives since 1684, that’s was how some students were able to catch with what was been taught in class.

  3. This is insightful. I’m looking forward to the next post as we hope to find answers to these questions.

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