Over the last few weeks, I’ve been reading Elizabeth Green’s new book How to Build A Better Teacher. It is full of gripping, play-by-play descriptions of the difficult intellectual work of teaching. In example after example, Green describes in vivid detail the flood of verbal, written, social, and emotional cues from students that teachers must notice, process, and respond to in every moment in order to maintain control of their lessons and effectively guide a room full of students through the learning process. The descriptions show how difficult good teaching is and why developing into an exceptional teacher typically requires focused training on proven teaching skills through many iterations of practice, feedback, and reflection.

One passage in the first chapter of the book illustrates just how complex good teaching is by comparing it to the work of medical doctors. The passage describes insights from Lee Shulman, a research professor from Michigan State who had studied the decision making processes of medical doctors, and then applied that approach to doing pioneering research in understanding teaching.

The question for teachers, as for doctors, was not, What is the best behavior? It was, How do I decide which of many behaviors to deploy for the case at hand? It was a problem of diagnosis. Teachers had to locate their pupils’ pathologies, determine a best intervention, and act. … Since the pathologies—that is, everything the child didn’t know—were not physical but mental, how could teachers diagnose them? How could they understand what a child had failed to learn? And if they did manage to teach successfully, how could they confirm it?

There was also the problem of scale. “The teacher,” Lee realized, “is confronted not with a single patient, but with a classroom filled with 25 to 35 youngsters.” Even if a teacher could locate pathologies and somehow do it for all her students, how did she manage to deploy the correct interventions, all at once, to the entire group? “The only time a physician could possibly encounter a situation of comparable complexity,” Lee concluded, “would be in the emergency room of a hospital during or after a natural disaster.”

That quote resonated strongly with me as I recalled my own experiences teaching. I think it captures, as well as any written work can, why teaching is so difficult and why good teachers, therefore, are so valuable.

Green’s book chronicles decades of research done by leading scholars and practitioners as they strive to take teaching from an art to a science. Her protagonists pour their life’s work into dissecting the craft of excellent teaching in order to prove that excellent teachers are not just born that way. Their work then points the way to how we might refashion teacher preparation and professional development so that all teachers can be as skilled and effective as the exemplars that the book describes.

I fully agree that improving the way we train and develop teachers is critical to improving education. But the complexity of teaching as described in the book also convinces me that to improve substantially the effectiveness of our teaching force, we also need to leverage technology to transform the way we organize instruction. As the quote from Lee Shulman points out, “The only time a physician could possibly encounter a situation of comparable complexity [to teaching] … would be in the emergency room of a hospital during or after a natural disaster.” In order to make dramatic improvements in the effectiveness of our education system, we do not just need better teachers. We need to move away from the batch-processing model of classroom instruction and use technology in order to simplify some of the complexities of teaching.

Fortunately, the advent of blended learning is making that reduction in complexity possible. For example, ongoing assessments embedded in software can gather real-time data on students’ understanding and thereby eliminate much of the guesswork that teachers currently have to do as they try to diagnose their students’ individual learning needs on the fly. Although learning software cannot teach with the depth and richness of an excellent teacher, it can provide individualized instruction on many basic concepts and skills. In these circumstances, it is effectively the next best alternative to having one teacher per student.

Using online instruction during school time also allows teachers to sub-divide their classes into smaller groups so that at any given time they can target their teaching to three to five students with similar learning needs, rather than struggling to diagnose and treat the learning needs of 20 to 25 students all at once. Technology can also streamline many of the logistical activities in a classroom, such as taking attendance, grading simple quizzes, or collecting assignments, so that teachers can focus more of their mental energy on teaching.

Green’s descriptions demonstrate clearly that we are not going to replace teachers with technology any time soon. Nonetheless, online learning has much to offer when it comes to reducing the complexity of teaching so that good teachers can be even more effective. In our current system, even the best teachers are not able to meet all of their students’ learning needs all of the time. But as blended learning continues to evolve and improve, technology can amplify the effectiveness of great teachers to turn our ideal into reality.


  • Thomas Arnett
    Thomas Arnett

    Thomas Arnett is a senior research fellow for the Clayton Christensen Institute. His work focuses on using the Theory of Disruptive Innovation to study innovative instructional models and their potential to scale student-centered learning in K–12 education. He also studies demand for innovative resources and practices across the K–12 education system using the Jobs to Be Done Theory.