No. 1404:

Today, let's talk about the prequisite course. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

Rereading a set of articles in last year's Science magazine has set off all my alarm bells. Educators, concerned over the way American science students have slipped behind, are recommending an integrated curriculum. Let's see what that means.

Most high schools start students out with biology. Then they teach chemistry and finally physics. That way they go from the course seen as least mathematical and most descriptive to the one regarded as most mathematically and conceptually difficult. The reason we teach biology as a purely descriptive course is that it's really so complex that few teachers can handle its full details.

So these courses get taught independently of each other. Biology texts raise issue after issue that can't possibly make sense without physics and chemistry: reaction rates, pH, chemical bonds.

Chemistry in turn is laced with concepts from the physics course that students haven't yet taken. So science begins to look like no more than a recitation of words. Students have little basis for appreciating the structural way the concepts bind one another together.

Science is quite different from, say, history. Humanities students develop maturity in a mosaic fashion. Learn about Byzantium one semester and English kings the next. The order isn't important, because the big picture emerges from many tiles. Far more than biology, history is too complex to be based on simple sequences.

To teach science, we have to reveal a mathematical and logical structure that comes to rest on concepts and equations. To understand science, we have to develop an architectural eye for its structure. That architecture can no more be broken into isolated units than a building can be reduced to a collection of rooms.

The structure of science should be seen, not as the essence of scientific complexity, but rather the essence of scientific unity and simplicity. That's why educators rightly call for an integrated science curriculum. By that they mean teaching math, physics, chemistry, and biology in that general order but all of a piece, building up the logic and the structure along the way.

Meanwhile, the result of teaching science in isolated sections has been more devastating than we realize. Students who've seen science reduced to description are left with only words. And the architecture of course sequences -- the heart of science education -- makes less and less sense. That's why college students sell their textbooks at the end of a semester and expect the next course to be a tabula rasa -- a new beginning untouched by previous study.

This is subtle business. Science offers so many lovely and compelling phenomena that we're seduced into thinking we're teaching science when we're only describing raw data. The Latin word scientia means ordered knowledge. Until we've conveyed the architecture of that order, we've taught very little indeed.

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.

(Theme music)

Mervis, J., U.S. Tries Variations on High School Curriculum. Science, Vol. 281, July 10, 1998, pp. 161, 163.

Bardeen, M.G., Lederman, L.M., Coherence in Science Education. Science, Vol. 281, July 10, 1998, p. 178.