By Robert Talbot, The Chronicle of Higher Education
It’s great for learning about a subject; inadequate for higher-level thinking.
Let’s start with what Khan Academy is. Khan Academy is a collection of video lectures that give demonstrations of mechanical processes. When it comes to this purpose, KA videos are, on the average, pretty good. Sal Khan…is approachable and has a knack for making mechanical processes seem understandable…. His videos are not perfect. He tends to ramble; he doesn’t use visuals as effectively as he could; he’s often sloppy and sometimes downright wrong with his math….
But let’s also be honest about what Khan Academy is not. Khan Academy is not a substitute for an actual course of study in mathematics. It is not a substitute for a live teacher. And it is not a coherent curriculum of study that engages students at all the cognitive levels at which they need to be engaged. It’s OK that it’s not these things. We don’t walk into a Mexican restaurant and fault it for not serving spaghetti…. Khan Academy is a great resource for the niche in which it was designed to work….
When we say that someone has “learned” a subject, we typically mean that they have shown evidence of mastery not only of basic cognitive processes like factual recall and working mechanical exercises but also higher-level tasks like applying concepts to new problems and judging between two equivalent concepts. A student learning calculus, for instance, needs to demonstrate that s/he can do things like take derivatives of polynomials and use the Chain Rule. But if this is all they can demonstrate, then it’s stretching it to say that the student has “learned calculus,” because calculus is a lot more than just executing mechanical processes correctly….
Even if the student can solve optimization or related rates problems just like the ones in the book and in the lecture — but doesn’t know how to start if the optimization or related rates problem does not match their template — then the student hasn’t really learned calculus. At that point, those “applied” problems are just more mechanical processes. We may say the student has learned about calculus, but when it comes to the uses of the subject that really matter — applying calculus concepts to ambiguous and/or complex problems, choosing the best of equivalent methods or results, creating models to solve novel problems — this student’s calculus knowledge is not of much use.
Khan Academy is great for learning about different subjects. But it’s not adequate for learning those subjects on a level that makes a difference in the world. Learning at these levels requires more than watching videos and doing exercises. It takes hard work (by both the learner and the instructor), difficult assignments that get students to work at these higher levels, open channels of communication that do not just go one way, and above all a relationship between learner and instructor that engenders trust….
Khan Academy [can] play a useful role in learning calculus or some other subject…. But mechanical skill is a proper subset of the set of all tasks a student needs to master in order to really learn a subject. A lecture, when well done, can teach novice learners how to think like expert learners; but…with Khan Academy videos, this isn’t what happens — the videos are demos on how to finish mathematics exercises, with little modeling of the higher-level thinking skills that are so important for using mathematics in the real world.
So the kinds of learning objectives that Khan Academy videos focus on are important — but they’re not enough. And I’m troubled when people say that they are enough, that Khan Academy videos are great because “they work,” and redefine mathematics to be the study of how to perform hand-calculations and pass mathematics exams….
I’m not a Khan Academy hater. I’ve used the videos…as far back as 2008, before KA made it big…. But I’m not an uncritical fan. We need to look carefully at Khan Academy before we adopt it, whole-cloth, as the future of education.
Robert Talbot teaches math at Grand Valley State University (Allendale MI)