Lectures in Their Proper Place

In my previous post, I reported that MIT was getting rid of lectures in their physics classes.

In the New York Times article about this change, Carl Wieman, a Nobel Prize-winning physicist who directs a science education initiative at the University of British Columbia is quoted as saying that the human brain “can hold a maximum of about seven different items in its short-term working memory and can process no more than about four ideas at once.”

“But the number of new items that students are expected to remember and process in the typical hourlong science lecture is vastly greater,” he continued. “So we should not be surprised to find that students are able to take away only a small fraction of what is presented to them in that format.”

This relates to the problem of attentional resources I discussed on November 21st.

If organized well, lectures can distill a vast amount of information down to a few principles and key examples. A lecture can be an economical introduction to a subject. The best lectures essentialize the subject matter conveyed by the lecture.

However, as a method, lectures are designed to be easy for the teacher, not the student. They allow the teacher to recount his or her knowledge without feedback or interrupting questions and side issues from the listener. Although sometimes necessary, lectures are usually a difficult way to learn because they frequently run counter to human learning tendencies.

For several reasons, students must exert an enormous amount of effort to stay focused on what the speaker says during lectures. A lecture requires the learner to mostly listen and look a little. Unlike learning methods that make learning easy, the lecture does not engage the whole mind, including vivid perceptions and imagination, or the body of the student. Listening and looking during a lecture involves little sensory-motor work, which normally helps cement learning in memory.

One of the reasons visual aids such as Microsoft^® Office PowerPoint^® are preferred for lectures is because they offer sensory stimulations, providing at least some perceptual imagery to associate with the ideas being conveyed. Although, like books, lectures can have illustrations, the student cannot study the illustrations in a lecture as long as he or she wants.

Human interaction usually helps to increase interest as well as physically engage the student, but during a lecture, there is very little interaction between student and teacher. Often the lecture is aimed at a large or general audience and thus cannot address individual student goals, interests and comprehension difficulties.

A student cannot stop the lecture to ask a question or request a further, clarifying explanation. Once confused, the student finds the rest of the lecture very difficult if not impossible to follow. Consequently, students often miss the important points and substantial content of the lecture.

In a lecture format, the best teachers attempt to address human learning needs by weaving their information into a story, incorporating drama, character, values, passion, meaning, purpose, a climax and resolution. Winston Churchill was a master at this. This method utilizes human tendencies to search for meaning and purpose, to connect knowledge acquired to personal circumstances, and to remember people, places and things more easily than abstract ideas.

Excellent lecturers use plenty of concretes to make the information vivid and connected to real experience and, at least in imagination, to stir perceptual memory and bodily feelings of the student. Imaginative work and bodily feelings help the student feel much more engaged in the material. Exceptional lecturer MIT physics professor Walter Lewin spends 30 hours and three practice trials developing each of the lectures for his remarkable class.

The best learners can gain from almost any lecture; they come to a lecture motivated to learn for their own reasons. They expend extra effort in imagining their own examples in order to concretize the ideas they’re hearing. As they listen, they maintain an internal dialogue of questions with the lecturer, noting what they don’t understand and with what they take issue. They also tend to seek answers to their questions after the lecture.

Many teachers recognize that this kind of student is rare and usually has high intelligence, strong intellectual ambition, and great self-motivation. For the most part, traditional education methods do not nurture internal motivation and inherent interest in acquiring knowledge—qualities essential in the new global economy.

A long school career of lectures, drills, memorization, and teaching methods out of tune with learning needs usually turns most students away from enthusiastic learning at school. They are only too often motivated mainly by external rewards of grades, adult approval, superior social position and the acquisition of credentials.

Unfortunately, lectures are so difficult to pay attention to, and psychologically painful for most students, that students work hard to avoid them. During lectures, any younger students merely goof around; consequently, they learn that they are “bad” and “undisciplined.” They are expected to know how to force their attention on boring material.

Students attempting to pass their courses seek low-energy ways to fulfill requirements while maximizing grades, such as the use of tape recordings, buying others’ lecture notes, or passing multiple choice tests without attending lectures.

These students aren’t inherently bad, they are responding to the high psychological costs of traditional education in a psychologically economical way. They more profitably spend their limited attentional resources elsewhere.

Sadly, they often feel guilt, frustration and anger for failing to live up to the traditional classroom’s expectations, with a nagging disappointment for what they’ve missed—or should have gotten—from education. Many students desperately need help to become active learners, interested in the material and in charge of their own education.