Are lectures evil?

by Stephanie Chasteen on September 14, 2009

No, of course not.  But to hear us education folks prattle on, you’d think that an instructor who lectures to their students is doing them a grave disservice.

Well, if all they’re doing is lecture, then their students could be getting more bang for their buck.  But lecturing is perhaps an indispensable part of class, especially in large college courses.  I’m reading a great article right now on how to make lectures more effective — here are some tidbits from that article (P.A. deWinstanley and R. A. Bjork, “Successful Lecturing:  Presenting Information in Ways that Engage Effective Processing,” in Applying the Science of Learning to University Teaching and Beyond).

Firstly, people need to be active in order to learn.

Toward achieving the goal of having students actually learn during lectures, it is important to remind ourselves of some fundamental properties of humans as learners. Learning does not happen, for example, through some kind of literal recording process. Rather, learning is an interpretive process: new information is stored by relating it to, or linking it up with, what is already known.

So, in lecture, we need to be able to spark the kinds of cognitive processes that actually help people learn.  For one, students’ attention can’t be divided if they’re to fully process what we’re trying to teach.  But Powerpoint and other tools require students to both attend to something visual (the screen) while they process something auditory (what we’re saying).  The end result seems to be that students think they understand, but can’t actually recall the material on the test  (Note the implications for students’ tendency to multitask during class!)  That’s horrible — students leave with the impression that they don’t need to study because they know the material, but they really don’t.

It’s also important that students, once their attention is directed, have a chance to interpret and elaborate upon what is presented in lecture.  New information has to be fit in with what a student already knows.  A graph, for example, isn’t easily memorized.  But once a student has determined what that visual information represents, and used it to answer a question, he will more likely recall the graphic or its message.

In order to remember information, it’s also important that students be given a chance to generate and retrieve that information.  The act of recall strengthens neuronal connections, creating learning.  That’s why it’s helpful to test oneself when studying for a test (and this is useful even if you aren’t given the answers about whether you’re right or not, though feedback is more helpful).  Producing information helps us learn more than being presented with that information.  Even something as simple as having to fill in missing blanks in a word (eg., “try to incorporate g-n-r-t-ng into your lecture”) results in better learning than reading that same word in bold (eg., “try to incorporate generating into your lecture.”)  Of course, the use of personal response systems (“clickers”) fulfills this end very nicely.

A few presentation tips from the article:

Space repetitions of information across lectures.  Long term recall is improved when information is spread out over time.  That’s why it’s better to study over several days, rather than cram the night before the test.

Show key concepts in several different ways. This is termed “encoding variability,” and gives students a chance to learn the material in more than one way, which helps them generalize what they’ve learned.

Provide structure. This is the goal of the ubiquitous outline we see in talks, lectures, syllabi, etc.  Some studies have found that students learn a lot from filling in an instructor-prepared outline of lecture notes (eg., headings and subheadings), rather than taking lecture notes on a blank piece of paper.  Concept maps are also useful ways of helping students see the big picture.

Use visuals and mnemonics. This is another way of increasing encoding variability, or the different ways in which students process the information that’s being presented.  Vivid examples and analogies can help, as can graphs, figures, or having students produce their own diagrams.  Enthusiasm and humor, well-placed, can also serve as a mnemonic.

Ask students questions. Ask students questions in class, and require them to give the reasons behind their answers.  Again, clicker questions are a great way to do this, and to make sure every student has a chance to explain their reasoning (at least to their peers).  To get the real benefit here, the questions have to be genuine questions, not rhetorical.  So many instructors ask a question, and then answer it themselves, lulling students into a certain passivity.

So, there are many ways to make lecture an extremely positive learning experience for our students.  But simple enthusiasm and clear explanations aren’t enough.

Here is the original chapter if you’d like to read it.

(P.A. deWinstanley and R. A. Bjork, “Successful Lecturing:  Presenting Information in Ways that Engage Effective Processing,” in Applying the Science of Learning to University Teaching and Beyond).

{ 1 comment }

Dr. Sanford Aranoff September 19, 2009 at 12:51 pm

Yes, we have to understand how students think, and build from there using basic principles and logic. See “Teaching and Helping Students Think and Do Better” on amazon.

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