One day about eight years ago, Cabot Professor of the Natural Sciences John E. Dowling and Baird Professor of Science Dudley R. Herschbach invited a colleague out to lunch.

"[They] said they had this project they'd been involved in for some time-to reform curriculum for people in life sciences, especially pre-med," recalls Menzel Professor of Astrophysics David Layzer.

"We wanted to have a better sequence of courses leading up to biology courses that would actually use chemistry and physics," he says. "I'd been teaching large core classes which met in small discussion sections, and they asked me if I'd be interested in forming this new introductory course."

What Layzer created is one of the most innovative courses at Harvard. As an alternative to Chemistry 10, Layzer and Professor of Chemistry Cynthia M. Friend now offer the year-long sequence Chemistry 8 and Chemistry 9.

The course, which is open to students who place into Chem 10 and Math 21a, combines physics, chemistry and math in a small group setting rarely found in other science classes.

Most students in the class are also concurrently enrolled in a small section of Math 21 tailored especially for the course. When taken with these math sections, Chem 8 and 9 fulfill the physics, math and general chemistry requirements for pre-med students.

The course is unique among introductory science courses because students meet in small, bi-weekly discussion groups and receive grades based on problem sets rather than on finals.

Creating the course has forced Layzer and Friend to devise a new method for teaching chemistry and physics. When Layzer began work eight years ago, one of his first steps was to replace the typical science textbooks used in introductory chemistry and physics courses.

"Introductory chemistry and physics books can't possibly be read--they're more like reference books," he says. "I set out to write not a textbook, but a narrative, with a lot of examples and a real story. It would have a plot and a beginning and end, and be in the language of science and math."

Layzer also says that while the narrative covers chemistry and physics, it is intended to teach the subject matter as it is relevant to life science majors. He says, "I began with molecular biology textbooks and worked backwards, thinking. "What would you need to know to understand this?"

The result of this work is a class which, while extremely challenging, is very popular with the students who take it. It is a dynamic course, where Layzer and Friend frequently experiment with the teaching approach.

In the course's first year, it was "much, much too hard," Layzer says. "The course has gotten more pleasant to take, but not watered down. The material has been better adapted to the way a human mind works."

In its unique approach and small, intimate class size, Chem 8 and 9 may hold important lessons for instructors in other science courses, particularly introductory ones.

"This class is very intensive in terms of teaching staff--we need a lot of instructors," Friend says. "It is interesting to think how the subject material and approach to teaching could be used for a larger group of students."

Integrated Approach

Chem 8 and Chem 9 give students the same credit as two more common introductory courses, Chem 10 and Physics 15a. But undergraduates and instructors in Chem 8 and 9 say their class presents chemistry and physics in an integrated way.