Good teaching may be tough to quantify -- it's part personality, part performance art, part mind reading -- but it's easy to recognize, and the Faculty of Arts and Sciences has done just that in naming six outstanding undergraduate teachers to Harvard College Professorships.

The honor was established last year and rewards Harvard's great teachers with a five-year chair that contributes to the recipients' professional development with either a semester of paid leave, commensurate summer pay, or an equivalent fund to support their scholarly work.

This year's recipients are Professor of Chinese History Peter Bol; John Dowling, the Maria Moors Cabot Professor of the Natural Sciences; Eric Mazur, the Gordon McKay Professor of Applied Physics and professor of physics; Professor of Government Michael Sandel; Richard Tarrant, the Pope Professor of the Latin Language and Literature; and Professor of Sociology Mary Waters.

The professorships were established through a gift from John L. Loeb, SB '24, LLD '71 (hon.), and Frances Lehman Loeb. The Faculty of Arts and Sciences will announce several chairs each year until 24 are serving at any one time. Five professors were honored last year, the program's first.

"Many universities give prizes to their committed teachers, and at one, the president presents popular professors with an apple," said Dean of the Faculty of Arts and Sciences Jeremy R. Knowles. "In this Faculty, thanks to the generosity of John and Frances Loeb, we reward our most inspiring and dedicated teachers more tangibly. I am very happy to recognize the great contributions of Harvard College Professors to the educational experience of undergraduates in the College."

Selections are made based on several criteria, including student ratings of individual professors, section and tutorial teaching, advising of senior theses or research projects, and service on committees that help with undergraduate education, according to William Todd, dean of undergraduate education in the Faculty of Arts and Sciences.

Todd said the honor is important because it shows that Harvard values the teaching of its faculty as much as their research and scholarship.

"It signals to the faculty, the students, and to the world outside that we value not only research, but also teaching," Todd said. "It also reinforces the link between great teaching and great research by rewarding our great teachers with the opportunity to move ahead with their research, which made them inspiring teachers in the first place."

The Recipients

Professor of Chinese History Peter Bol uses several tactics to keep tabs on how his students are faring, but it all boils down to paying attention.

One year, he said, students began applauding at the end of every lecture. After the habit was established, however, the students were too polite not to applaud when they didn't understand or when a lecture bombed. But, Bol said, he could tell how the lecture went just by how vigorously the students clapped at the end.

Today, the clapping is over, but Bol still tracks his students, gauging their responses by their faces. He said it helps to be a bit of a perfectionist.

"I always worry I'm not getting across. I always suspect they are not following the thread. I always know I need to do better," Bol said. "In the end, however, it really does require having learned something interesting that you believe the audience will want to hear about."

Maria Moors Cabot Professor of Natural Sciences John Dowling's commitment to undergraduate education extended far beyond the classroom for the 17 years he served as Master of Leverett House, a post he retired from last year. Though he is no longer Leverett Master, Dowling's commitment to undergraduate education hasn't wavered.

Dowling has taught science to large lecture halls of undergraduates for years, and has worked with hundreds of undergraduates and graduate students in his research lab, where he studies the vertebrate retina. Dowling describes his teaching style as a bit old-fashioned, with extensive use of the blackboard. But he strives to ensure that at the end of each lecture, students really understand the subject of the day.

"I've enjoyed undergraduates very much over the years, watching them grow," Dowling said. "It extends not just to residential life, but to research. I've had more than 100 postdoctoral, graduate, and undergraduate students through this lab."

Dowling said he tunes into things like background noise and shuffling papers to tell when he's not reaching students and tries to use question-and-answer formats to keep students engaged.

"You monitor faces," he said, adding that the trick is to pick the right faces. "Some look bored all the time -- they're no good [to use as a gauge]; others are enthusiastic all the time -- they're also no good."

Gordon McKay Professor of Applied Physics and Professor of Physics Eric Mazur said his current teaching style is the result of an epiphany several years ago. He'd been teaching physics to undergraduates for six years when he discovered that, though his students were very good at using formulas and plugging in the right values to come out with the right answers, they really didn't understand the concepts underlying the formulas.

It was a bit of a shock, Mazur confesses, and caused him to begin to search for ways to spark that broader understanding. The answer came not from increased order in his teaching, but from chaos, he says.

Mazur has adopted a read-first-lecture-second style in which he doesn't repeat the reading during his lectures, but instead tries to gauge what students didn't understand in the reading and fill in the gaps.

One of the ways he finds the gaps is by giving the students questions that test the students' conceptual, rather than mathematical, understanding of the principles of physics.

An example is a problem of a boat with a rock in it floating on a lake. If the rock is tossed into the water, what happens to the lake's water level?

Mazur will throw the question out and let students hash out the answer. He then lets the students try to convince each other that their answer is right. Invariably, Mazur said, the students with the right answer will convince the others until a sizable majority agree on the answer. The method provides a good way of getting feedback as well, Mazur said, because if more students support the wrong answer, it means he has more explaining to do.

"The amazing thing is the students who are right invariably convince those who are wrong. Maybe they should get the award," Mazur said. "I consider myself a coach more than a teacher. I've given up trying to pour knowledge into students' heads."

Professor of Government Michael Sandel has long taught one of Harvard's most popular fall semester courses, Moral Reasoning 22: Justice.

In Justice, Sandel challenges 700 to 900 students with texts by Aristotle, Locke, and Kant and with arguments about topics relevant today, such as affirmative action, income distribution, and the difficult balance of free speech versus hate speech.

Sandel, who is on leave this semester, has previously been singled out for recognition of his teaching skills. In 1985, Sandel was awarded the Harvard-Radcliffe Phi Beta Kappa Teaching Prize and, in 1987, he was singled out by Insight magazine as one of "nine great teachers" in a survey of U.S. college professors.

Sandel said the large class size actually helps foster learning. So many students are reading the same texts and wrestling with the same moral dilemmas, he said, the discussion continues outside the classroom.

"My job is to provoke the discussions and give them some structure," Sandel said. "The Justice course is built around argument. Students find it exhilarating, if somewhat risky, to subject their moral and political convictions to critical examination. We engage the philosophical texts, not as relics in the history of ideas, but as episodes in arguments in which we are still engaged."

Pope Professor of the Latin Language and Literature Richard Tarrant said he feels lucky to be teaching the giants of classical literature, whose writings have had a profound impact on modern culture, to today's students. And Tarrant's excitement and enthusiasm help keep students involved and interested. He also spurs students to discussion about the writings, making them "collaborators in a joint enterprise of interpretation."

Tarrant said his teaching and research complement each other. In producing editions and commentaries of primary texts, Tarrant is constantly looking for new ideas and interpretations of the classic works. Those same ideas and interpretations can then be introduced in the classroom. Classroom discussion can, in turn, spark new ideas.

"As for the stimulus of teaching, I can think of no better way to keep my ideas fresh and to advance in understanding," Tarrant said. "I feel most excited about going into a class when preparing for it has enabled me to see something I hadn't noticed before or to make a connection I hadn't realized could be made. Being open to new ideas about familiar texts makes it more likely that fresh insights will emerge in the class discussion itself, and that's the most exciting thing of all for a teacher."

Teaching runs in the family for Sociology Professor Mary Waters. Not only is she the child of two college professors, but four of her seven brothers and sisters are also educators. Waters said she's always felt at home in the classroom and says she stays in touch with the students by talking to them to find out which teaching techniques work and which don't.

A key element, though, she said, is maintaining her enthusiasm for her subject. She continues to incorporate new readings and new topics, and to introduce issues and problems that she doesn't necessarily have answers to.

"The main thing I have found over the years is that if I am excited and engaged with the material, the class usually goes well and if I am bored the students know it and are bored, too," Waters said.

Waters added that it is important for Harvard to recognize excellence in teaching because the recognition puts teaching on a par with research and other scholarly activities.

"I know that Harvard has many, many wonderful teachers and advisers, so for me to be singled out is truly an honor, and one that was very unexpected," Waters said.