The "Overall Level of Effort" approach might provide a model for traditional schools to follow—and it suggests that one size need not fit all when it comes to student-teacher ratios.

What number of students should each teacher teach? How many is “too many”?

As a lifelong passionate fan of the teaching profession, I used to believe these questions had a pretty simple answer: The fewer the better. Throughout the class-size debates of the past 15 years, which have led to limits in the range of 20 students per teacher in California, Florida, and elsewhere, I was firmly in the “small is beautiful” camp. And while I still believe in the power of personalized instruction at the hands of a teacher with the time to focus on one student at a time, I have come to regard arbitrary student-teacher ratios as a holdover from the Industrial Age of education. Here in the Information Age, we have more precise instruments at our disposal. It turns out that the right answer is: It depends.

This change in my thinking has come about through my involvement since 2001 in online learning for grades K-12. The company I helped launch and still work for, Connections Education, is known for its high-quality, highly successful Connections Academy virtual schools and now also its Connections Learning line of curriculum and instructional services for school districts, state education departments, and other institutions. As the K-12 online and blended learning field has evolved over this past decade, I’ve found that the first misconception my comrades-in-arms and I have to dispel is that “online” means “teacherless.” Nothing could be further from the truth. National standards of quality for online learning from organizations like the International Association for K-12 Online Learning and the Southern Regional Education Board all stress the central importance of expert teachers in ensuring a successful online experience.

But how many students can each one of these expert teachers effectively teach? At Connections, we calculate this answer through a set of metrics we call “Overall Level of Effort,” or OLE for short. This begins with the understanding that the teacher does not have to literally deliver the content, any more than a tech-savvy face-to-face teacher does—the curriculum and supportive technology provide instant access to the facts. However, some content requires more mediation from a teacher than others.