|
Editor's Note: Reading about wonderful ideas for curricular
change is sometimes vastly different from making those changes work
in the classroom or laboratory. The authors this month describe specific
processes for change that have been used to introduce innovative learning
processes into their laboratory courses. In one case the content of
the course was not changed, but the timing was. In the second case
cooperative learning processes were introduced in order to facilitate
a change in the course content itself.
Traditionally, chemistry labs for our large lecture classes have consisted
of a 3-h period in which students apply the theory from lecture by
conducting a detailed experiment. Students are expected to read the
procedure and understand the experiment before attending lab. In order
to provide some additional background or hints regarding that particular
procedure, there is usually a lab kickoff provided by an instructor.
Although this instructor could be the lecturer for the course, it
is usually a graduate TA.
This format has worked well for many institutions, but unfortunately
this system has several flaws. When these kickoffs are held in the
lab, there is not time for the student to assimilate the information.
The students are often trying to get started with the procedure, or
they cannot hear due to background activity. They may be scattered
at benches throughout the room, etc. When the instructor's native
language is not English or if the instructor is not familiar with
the experiment, the students often do not understand the information
or are given incorrect information. Lack of consistency in these prelab
kickoffs from section to section also results in confusion.
The result is that students in these traditional chemistry laboratories
miss important information. Often they are apprehensive or unsure
regarding equipment setup or techniques or, in a worst-case scenario,
appear to be "cook-booking" their experiments. The students
often do not make the correlation between the lab procedure, a chemical
equation, and the theory from lecture.
In addition to these problems, rapidly rising enrollment (a 30-36%
increase within the last eight years) has resulted in an increase
in demand for chemistry courses without a concurrent increase in laboratory
space. Students have always had their own drawers of equipment located
within the lab. Because the number of enrolled students is traditionally
limited by the number of available drawers, the laboratory space is
greatly under-used. This, coupled with a concern that the students
are not truly understanding the lab component of the course and its
relationship to the lecture, has caused the chemistry department to
reevaluate the format and content of the laboratory sections of the
large-enrollment chemistry classes. The goal of these changes is to
increase the understanding of the lab procedures while accommodating
more students in less lab space.
Meeting the Challenges
In order to meet these challenges, we have divided our lab time
into a 1-h prelab and a 2-h lab experimental section. For the science-majors
organic course, which usually has 150 students subdivided into six
separate lab sections, the prelab is held in a classroom setting in
which the students can sit undistracted, take notes, and ask questions.
The instructor provides details of the experiment and information
on how to set up the lab equipment. Although quizzes on the lab procedure
are often given in these sessions, they are not traditional recitation
sections. Because our organic lab runs concurrently with lecture,
the first labs address techniques, such as various distillations,
extractions, and chromatography. We want students to become familiar
with these procedures, understand them, and apply them when running
more in-depth experiments. Later experiments cover more in-depth examples
of methodology from the lecture. Because the lab period is only 2
h, illustrative experiments are chosen that can be finished within
this time frame. The type of reaction is emphasized rather than a
specific reaction. (The oxidation of alcohols is the topic rather
than the synthesis of camphor from isoborneol.)
Students have the option of attending one of two available laboratory
lectures or kickoffs. These prelab lectures lasts 40-50 min. The
TA's are also required to attend these lectures to ensure that any
details or changes in procedure are understood. Because this prelab
lecture is critical to success, students are not allowed to attend
lab without it. The prelab is held in a variety of classrooms around
campus, so attendance is taken at the prelab using a bar-code reader
and the student's school ID card. This avoids tedious seating charts
(especially in rooms lacking fixed seating arrangements). In our system,
the TA's were responsible for taking attendance at the kickoff lecture.
Students who missed both of the lectures were given a 0 for that particular
lab.
Implementation
In order to ensure compliance with the attendance requirement
without seating assignments, we used a portable bar-code reader. The
student-registration information including names, identification numbers,
and section numbers were obtained from the registrar in ASCII format.
A centrally located personal computer and printer(2) and
a hand-held bar-code reader equipped with a numeric pad(3)
were loaded with bar-code communications software, a student tracking
program(4), and the registration records. A stockroom proved
to be an ideal location for the equipment because only faculty and
staff have access to the room.
Students are issued an ID upon registration that has their student
ID in bar code. Student have their school ID scanned upon entering
the lecture room. If students forget their ID, the number could be
entered manually using the keypad. After all the students were registered,
the bar-code reader information was downloaded to the computer via
a RS232 serial interface, and the data was sorted and printed. Each
lab instructor was given an attendance list. Students who had not
attended the lecture were listed separately.
In order to more efficiently use the laboratory space and equipment,
students obtain from the stockroom a "basket" of equipment
needed to complete the current lab rather than having an assigned
desk drawer. Students were not allowed to check out equipment or enter
lab without having attended the kickoff. The equipment was cleaned
and in good condition before it was accepted by the stockroom personnel
for return.
Feedback
Student and faculty feedback has been extremely favorable regarding
this arrangement, and we have received no negative feedback. Students
appreciated the freedom of flexible scheduling and the informal seating
arrangements. They also enjoyed "seeing" what they were to
do in lab and taking notes on the procedure. Having seen the setup
or, for example, the color change they should observe, the students
have the knowledge and confidence to make informed decisions in their
work. Generally fewer mistakes and accidents occur. The laboratory
instructor becomes an added resource, and the student questions that
arise during the lab tend to involve the chemistry being done rather
than the technique.
We are continuing to modify this system to allow for even more flexibility
in lab scheduling by developing a series of videotapes of the lectures.
The students would be allowed to attend any open lab section after
viewing the tape. We are also developing a system where the students
use the Internet to make a variety of tasks more convenient: rescheduling
lab times, checking grades, leaving messages for instructors, learning
about upcoming departmental seminars, etc. In addition, we are developing
a method of tracking equipment-breakage charges using the bar-code
reader in which all items will be assigned a bar code, and missing
or broken items will be directly charged to the breakage account of
the student.
Acknowledgment
The authors would like to thank Dr. C. J. Peterson and the office
of the Vice President for Academic Affairs for funding of hardware
and software.
References
- Author to whom correspondence should be addressed.
- We used an IBM XT 8088 with a dot matrix printer.
- We used a Videx Time Wand II and communucations software from Videx, 1105 NE Circle Blvd, Corvallis, OR 97330, (503) 758-0521.
- The program we used was The Student Tracking Program by Corner House Software, Box 19, Volga, SD 57071, (605) 690-1411.
|
Citation
