A computer – managed undergraduate physics laboratory

Seventeen one-semester undergraduate laboratory courses are managed by a micro-computer system at Concordia University. Students may perform experiments at any time during operating hours. The computer administers pre- and post-tests. Considerable savings in manpower costs is achieved. The system also provides many pedagogical advantages.

The use of computers in the laboratory is hardly new. The most obvious use as a sophisticated data collection device has appeared quite frequently in the literature. The use of computer interfacing is also a natural application. An obviously important application of computers in conjunction with laboratories is to simulate experiments or sophisticated apparatus. One application that has not appeared in the literature is the use of computers in the basic administration of laboratory courses. By having computers run tests before and after students take their labs, the entire laboratory system can be redesigned. Direct benefits are flexible schedules for students, capability to handle a large number of students without increasing the number of setups, uniform grading system, and considerable savings in manpower in supervisory laboratories.

The Concordia University Physics department has made use of an automated computer-managed laboratory system since 1966. The original system was based on an IBM 1620 computer and used com-puter-card-based tests. This evolved through terminals communicating with a remote mainframe to the present configuration which utilizes a Radio Shack micro-computer network.

The basic computer network used in the present configuration is inexpensive and the resulting computer-managed laboratory system has many advantages for the student body, the faculty, and the administration. Under this setup students may perform any experiment they wish at any time that the labs are open (2:00 p.m. -10:00 p.m. Monday through Thursday) simply by making a reservation for the next day or as far ahead as two weeks for the number of hours required.

In order to ensure that students are familiar with the experiments before attempting them, they must attempt a pretest for the specific experiment. After performing the experiment, the student must write a further test. At the end of the term, students are given a final test based on all the experiments performed during the year. Students are also required to submit lab reports on the experiments.

Since the labs are open for extended periods of time, fewer lab setups are required.

Any student attempting to perform an experiment or test without having done the pretest receives a grade of zero for the experiment. Since the students are familiar with the experiment before entering the lab, very few demonstrators are required. A single demonstrator is available at any time for the three introductory labs.

One further demonstrator covers the fourteen advanced labs. At peak periods at the beginning of the year one further demonstrator is used. Demonstrators are students. A single full-time operator is also required to run the Radio Shack Computer system. The entire operation is administered by a faculty member.

The Radio Shack computer setup consists of 16 64K model 4 student stations; two 64K units and one 128K unit (the latter with double disk drives) to administer the system; one network III controller; one DMP 200 printer with printer controller; one 25 Mb hard disk. Additionally two 128K units with double disk drives are used by the lab supervisor and the director of labs for use in handling student complaints and updating the systems. The last two units are also used as backups in case of system failure. A backup controller, printer, and hard disk are also kept ready. The backup hard disk is refreshed daily. Once a week the contents of the hard disk are copied onto floppy disks, which are stored in a bank vault against the remote possibility of fire or theft. The entire cost of the hardware was about 25,000 U.S. dollars. Prices have come down considerably since the time of purchase. In any case the cost is eas­ily recovered within a year due to the marked decrease in manpower required for the configuration.

Students may not take any material with them during pretests or semester finals. For the individual lab tests, students are only permitted their data sheets stamped and initialed by a demonstrator. A student presents a University ID card to the test room operator and indicates the course and nature of the test to be taken (pretest, etc.). The operator types the information into his micro-computer and roughly by the time the student is seated, a set of randomly selected questions has been downloaded to the student's micro-computer. The screen at all times shows the time remaining to perform the test. Within the time limit, students can move back and forth among the questions, change their answers as often as they wish, or make use of a built-in calculator program. Questions can be or three types, multiple choice, numerical, or keyword. Numerical questions are based on students lab results and are graded as correct if the answers fall within an anticipated range. The range is continually revised with the ageing of equipment. Keyword questions correspond to searches of a student answer for up to ten acceptable answers. After students sign off, their grades are immediately printed and given to them as they leave. In case of dispute, the lab supervisor or director of labs can have the system recreate the test. A special statistics package allows immediate comparison of the students' answers to any question with the answers given by the previous twenty students who were given the same questions.

Students enjoy the flexibility of taking labs whenever they wish. For faculty there are a number of advantages. Students learn more, since they come into the lab prepared for the experiment. Where useful, students can easily perform all experiments in a given order. Finally students perform their experiments by themselves instead of with a partner. Thus every student must perform and understand every experiment.