As I have mentioned in a previous post, Sal Khan makes a compelling point in some of his presentations: that the measurement of student:teacher ratio should be reconsidered as the number of students that a teacher is effectively instructing at a time, instead of being based merely on the number of students in the classroom.

A recent blog post from Education Sector makes a similar point while discussing the blended learning approach at Alliance Tennenbaum Family Technology High School.

Tennenbaum, a member of Alliance College-Ready Public Schools, uses a rotational model of blended learning in which students get instruction three different ways. They go to one of three stations for 40 minutes at a time within two-hour blocks: one group gathers for traditional direct instruction with a teacher, other students work independently online, and a third group gathers for collaboration with each other. The breakdown makes for an actual student ratio of just 16 to 1 – any teacher’s dream. (Emphasis added.)

This approach, of course, requires some management of the students who are working independently online, and of the students who are collaborating with each other. The blog post doesn’t explain how these students are managed, and if the teacher is responsible for these students while also instructing the other students then it would be a stretch to say the actual ratio is 16 to 1. Still, this approach echoes the point being made by Sal Khan, and raises the issue of how student:teacher ratios should be calculated.

Ed Sector’s reports and blog posts are valuable in their honest assessment of the benefits and challenges of blended learning:

Here on this eastside campus are all the benefits and challenges of adopting radical change. On the plus side, students are working toward competency (no D’s allowed) at their own pace in their own way. Teachers are freed from chores like grading math problems to do what they do best. Daily assessments pinpoint problems and drive instruction. On the flip side, classroom management can require Olympian multi-tasking skill, and the software frustrates teachers when it is not as interactive or diagnostic as it could be. Meanwhile, students are coming from well behind: 65 percent arrived here deficient in the credits they would need to graduate.

Tennenbaum just opened in the fall of 2011, so it is too early to judge progress. The most recent quarterly benchmark assessments show largely successes but also some disappointments. In geometry, students jumped from 8 percent proficiency (or above) to 27 percent. In 12th grade English, proficiency levels increased from 30 percent to 57 percent, and in U.S. History, proficiency jumped from 9 percent to 35 percent. But in chemistry, proficiency levels plummeted: from 41 percent proficiency to just nine.

The candid assessment of results (“too early to judge progress”) is particularly useful. We will be watching this and other programs for evidence of success.