Computer System Evaluates Students

In most Harvard lecture classes students who don't understand the course material can hide in the back of the room. But in Physics 11b, McKay Professor of Applied Physics Eric Mazur has created something of an electronic dunce cap.

Using a hand-held Macintosh, Mazur asks the students bonus questions while he lectures. The students then enter the answers on several Hewlett-Packard computers which circulate through the classroom. Mazur's Macintosh records the answers, grades them immediately, then stores the results.

Mazur and students alike can monitor the responses on a large screen at the front of Science Center B which acts as a seating chart. If a student answers correctly, their seat on the chart lights up in a shade of student answers correctly, their seat on the chart lights up in a shade of light blue. If the student is partially correct, a dark blue light appears. If the student's answer is completely wrong, their seat on the chart lights up bright red for everyone to see.

Mazur says the purpose of the system is not to single out students who are doing poorly, but rather to help him improve his own teaching.

"This is a low-tech, instantaneous system, that allows me to give feed-back to the students during lectures," Mazur said. "They log in. I ask them a question, and then I can determine, from the percentage of students who answer correctly, how well I am teaching the subject matter."

Chris J. Hernandez '96, a student in Mazur's spring term class, said the process is essentially good, though he has some reservations.


"The system is helpful when the screen shows graphs and the total number of right or wrong answers is given, but not when the students who answer the questions incorrectly or correctly are identified by colored lights on a seating chart," Hernandez said. "Professor Mazur does explain the material more thoroughly when a large number of people answer incorrectly."

Morgan A. Huse '96, who is currently taking the course, said the procedure is quick and easy, but he is not too sure if the the system is necessary.

"The system is a good one, but it takes too much time away from lecture," said Huse. "I would rather spend that time learning Physics than learning how to use these computers."

Students can receive up to 10 bonus points by correctly answering the in-class questions. Those points will be added to the each student's final exam score.

In previous years, Mazur has tested his students during lecture with written questions and responses, but the computers allow him instantaneous results.

There are currently 250 students in the course sharing a total of 60 computers. Each Hewlett Packard 95 costs approximately $300.

Funding for the project came from the National Science Centers (NSC), with one-third of the money coming directly from Harvard's Science Center. The cost of the computer hardware was slightly less than $20,000.

Mazur said the new system saves paper that would have been used for scantron evaluation forms, and the total cost of this project is less than that of the scantron system.

In addition, the system allows teaching fellows to spend less time grading papers and more time giving students extra help, Huse said