Lecturing and the absence of Learning

It seems to me that the argument propounded in the last posting, about learning from lecture, really is worth considering further. We need to know how to motivate students to learn, and whether or not the modality of information delivery is significant. Since these postings are solely concerned with mathematical based science, we eschew topics of interest to the larger community.

The punctuated model of learning that we have is historically embedded in our agrarian heritage. We know, for instance, that total immersion learning for languages works; works to such a degree that learning German in Germany is virtually trivial compared to learning German in 1 hour per every other day sections as usually done in American Universities. Clearly, immersion learning in calculus, which would be incredibly strenuous, would work better than what we do now, but no one is espousing it.

We start with the book, the text, the font of all knowledge. Any casual inspection of current textbooks, comparing them to past efforts, will show that they are significantly improved. Although the reading level has decreased, that decrease does not necessarily lead to intellectual pollution. The idea that students learn to solve canned problems leads critics to shake their heads, but the fact is that performing at such a minimal level is certainly a first step which is necessary before progress can be made. We all really learn by re-visiting the material at a spiraling level of sophistication, placing it into its niche within the intellectual space we are building. The re-visiting is important.

When I teach, I tease my students about what they've forgotten (and I've been criticized for it, and in fact punished for it) but the teasing has a purpose. They are studying a subject whose predecessor materials have been learned (and forgotten). They need to re-learn the material, now from the point of view that they need it for the current material they are muddling through. My teasing seems a better method than assigning them to re-learn the material. They're adults; assigning freshman materials is demeaning (IMHO). But teasing them, puts them in the position, after re-learning the material, of being able to feel superior (certainly to the freshmen who are struggling with the material) since not only have they easily re-learned it, but they did so for a reason which was absent the first time around.

We have all forgotten material that we've learned in the past, partly because this material was never used again, never needed again, and therefore buried under newly learned material which was more important (temporally).
The trick is to change the examining system so that precursor materials need to be known during examinations. This would make the re-learning of material worth while, and would motivate students to retain relevant material as they progressed. Like a muscle being exercised, what we know is what we've used recently. The longer the material has lain dormant, the less we remember about it. If our examinations did not excuse precursor ignorance, we would change the culture of learning, so that as we progressed, as we learned more and more (about less and less?) we would retain more of the precursor material we see now disappearing.

Lecturing and Learning

"Lectures were created as a means of transferring information from one person to many, so an obvious topic for research is the retention of the information by the many. The results of three studies-which can be replicated by any faculty member with a strong enough stomach-are instructive. . . . . ."Hrepic et al. (2007)¨. . . asked 18 students from an introductory physics class to attempt to answer six questions on the physics of sound and then, primed by that experience, to get the answers to those questions by listening to a 14-minute, highly polished commercial videotaped lecture given by someone who is supposed to be the world's most accomplished physics lecturer. On most of the six questions, no more than one student was able to answer correctly. . . . . . These results do indeed make a lot of sense and probably are generic, based on one of the most well-established-yet widely ignored-results of cognitive science: the extremely limited capacity of the short-term working memory. The research tells us 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. Exactly what an "item" means when translated from the cognitive science lab into the classroom is a bit fuzzy. But the number of new items that students are expected to remember and process in the typical hour-long science lecture is vastly greater. 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."

(Wieman, C. 2007. "Why Not Try a Scientific Approach to Science Education?" Change Magazine, September/October; online.See also Wieman & Perkins (2005).)

They (and similar studies) have set up a straw man and then knocked him down. I am not interested in the short term learning during or just after lecture. I expect the student to review the material covered, test it against reasonableness, and incorporate it (or not) into his/her psyche. If s/he thinks its wrong, I want the student to come back and argue. If after a history lesson, which is surely solely memorization, i.e., no concepts whatsoever, a student can't remember a factoid from the first few minutes of the lecture, has the lecture failed?

One forgets that from a scale point of view, lecturing is the only effective method of instruction absent distance learning (an as yet unproven technique). From time immemorial, elders have spoken to youth instructing them. There was no other method of instruction, absent one-on-one tutoring, which is never cost effective. And one-on-one instruction is not failsafe anyway. There used to be a folk's tale concerning John Hopkins, a pupil, and a log, but in actuality, one teacher with one student is neither necessary nor sufficient to guarantee learning.

What we forget, IMHO, is that teaching and learning are not the same thing. Teaching means presenting the material. Good teaching means being able to present it is more than one modality, more than one phraseology, more than one viewpoint. But ultimately, teaching means telling a pupil something (perhaps in more than one way) and hoping for learning.

But learning is the pupil's problem, not the teacher's.

Learning is the student's responsibility. S/he can't just absorb it on the fly. Practice makes perfect holds in school as well as in getting to Carnegie Hall.

Most important, it is absurd to think that today's student can learn from the printed page. The texts are now dumbed down enough that anyone who can read can learn from them. But our students can't (IMHO) read for comprehension. They read for pleasure if at all. They come from households (IMHO) without books in them, with parents who do not read (IMHO) (even a newspaper) and from places where the television is on full time (IMHO). They expect to be entertained, and they expect that learning is fun and games. Even their obsession with video games translates into an inability to learn from the WWW. As adults, we've given up on them, and allowed the bifurcation of students into two groups, those from parents who have some modicum of technical ability and care, and the others.

Consider that most parents can not help their children with algebra homework, and undermine the school by saying that they "never understood it" at the time. Why should students strain for understanding when their "successful" parents never needed algebra? When we devalue learning as parents, we can not expect our children to want to learn.

Technically educated parents can hover over their children, correcting their mistakes, knowing the material their children are learning. So what we are developing is a society of two "cultures" which I call the those who can and those who can't do algebra.

Just as we see the enormous drop out rate amongst some students, we see and ever increasing achievement shown by highly precocious students vying for the limited number of spots at prestige Universities. This bifurcation makes second rate Universities into glorified high schools, and prestige Universities into elitist institutions. What a problem; but we've drifted away from lecturing and learning. Sorry.

Returning to lecturing, one notes in real lectures that most of the students are not engaged in the slightest. The only time we really have their attention is during examinations, and it is interesting that Computer Assisted Testing proposals have all recognized that only when interactively facing material under test do we get a reasonable facsimile of wholehearted engagement.