Education Life Supplement BLACKBOARD: In Class, Gadgets for Interacting, and No One
Need Nod Off By Eric Goldscheider
Teachers since Soc-rates have
known that students learn best when they are engaged. But most undergraduates endure more than one course in which a professor
holds forth for 80 minutes at a stretch. Some students just cannot help nodding off.
to Louis Abrahamson, a South African-born scientist, more are able to stay awake. Dr. Abrahamson, who had run a company that
preformed research for the National Aeronautics and Space Administration, said he decided 13 years ago that it was time to
pursue his dream of using science to benefit mankind more directly, so he set out to use microchips to liven up lectures.
A growing number of so-called classroom communications systems has resulted.
The systems come in
two varieties: hard-wired and wireless. Personal keypads allow students to answer questions posed during class.
Eric Mazur, a Harvard physicist who has used these systems for 10 years, might ask the 250 students in his introductory
lecture whether the level of a glass of ice water rises, falls or stays the same as the cubes melt. He posts possible answers
on an overhead projector and tells the students to vote. Individual responses are recorded on a hard drive, and the aggregate
is projected onto a screen as a bar graph.
The really interactive part begins when Professor Mazur
tells his students to convince their neighbors that their answers are correct before voting again.
class just erupts into total chaos," he said. "Nobody eats a sandwich or sleeps or even daydreams." Something happens pedagogically
when a person takes a position, commits to it, and is forced to defend or re-evaluate it that just does not happen during
an ordinary lecture, Professor Mazur says.
Classtalk, the original hard-wired system, is sold by
Better Education Inc., of Yorktown, Va., which Dr. Abrahamson heads. It costs about $22,850 to install in a 300-seat lecture
hall. Students plug a graphing calculator (about $85), standard equipment for science majors, into permanent jacks.
With a wireless innovation named the PRS for personal response system, each student has a transmitter that resembles
a hand-held calculator. Clicking the transmitter sends infrared signals to a receiver at the front of the room. It does not
collect as much information as the hard-wired system does, but the PRS system is portable and much cheaper. Installing the
system in a 300-seat auditorium costs about $800. Typically, students buy the transmitters at the bookstore for $50 apiece
and can take them from class to class.
The Hong Kong University of Science and Technology recently
became the first school to install classroom communications systems campus-wide.
Dr. Abrahamson said
the systems had also been used with great success in classes for much younger students.
By the way,
the Archimedes principle says that the water level in a glass remains unchanged when ice cubes submerged in it melt. Try explaining
why, and you will understand why Professor Mazur's class erupts into chaos from time to time.