Biology
California State University, Los Angeles
Interactive simulations draw students into electronic classroom
Reproduced with permission from NeXT
Computer, Inc.
A Reference
Guide to NeXT in Higher Education, Fall 1992
ยช
1992 NeXT Computer, Inc
California State University, Los Angeles (CSULA), is a
teaching university. Faculty pride themselves on working
daily with the 21,000 students who attend the institution.
However, because English is not the native language of the
majority of students and because most are accustomed to
academic standards different from CSULA's, teaching and
learning in the traditional classroom environment are
sometimes frustrating for faculty and students.
To improve the faculty's ability to educate students,
Robert Desharnais, assistant professor of biology, and Gary
Novak, professor of geology, proposed creating an
interactive electronic classroom for mathematics and
science students. After reviewing Desharnais and Novak's
proposal, "The Interactive Electronic Blackboard for
Natural Science and Mathematics Education,"the National
Science Foundation awarded CSULA a $100,000 matching grant
in 1991 to implement the classroom, which includes
NeXTstation Color machines and incorporates applications
developed by faculty combining NeXT bundled software and
commercial applications.
According to Desharnais, the program's objective is to
substantially increase the retention rates of mathematics
and science students, paying particular attention to
nontraditional students-those with weak academic
backgrounds and English-language skills. Faculty expect to
achieve results of regional and national significance.
Desharnais also believes the electronic classroom will
improve communication between faculty and students.
"Using the NeXT machines, students will be able to
participate more in the classroom," says Desharnais. "For
example, NeXTmail is one of the applications that is used
as an electronic blackboard-an interactive experience,
using sound, text, and graphics. The learning process will
be much more interactive."
Since winter 1992, Desharnais has taught several courses,
including undergraduate- and graduate-level ecology and
genetics classes, in the electronic classroom, using custom
applications.
For his genetics courses, Desharnais designed FlyLab, a
genetics simulation program that illustrates the principles
of Mendelian inheritance. Using FlyLab, students create
flies, mate them, and examine the offspring. Mendelian laws
of heredity are graphically illustrated in FlyLab, enabling
students to observe the transmission of genetic qualities
from parent to offspring.
"I designed FlyLab because it's impossible to do all the
variations and crosses in a lab experiment," he says. "If
something goes wrong, that's it-students don't see results.
FlyLab provides tremendous flexibility. Students see
mutations such as curly winged or wingless flies, and they
can actually see what the fly looks like."
Selecting from many possible mutations identified in
FlyLab's Construct-a-Fly window, students build flies and
mate them by dragging two flies into the Mating Window.
Clicking the Mate button yields a window showing the
offspring. Any two flies can be mated to produce another
set of offspring. Students examine the offspring to learn
genetic inheritance rules.
"I had been teaching this class using BASIC in a DOS
environment, but I was really limited in what I could do
with command-line programs," says Desharnais. "Without the
graphical interface, students look at it as a chore. They
don't get to see what the fly looks like, and they often
forget what the mutation looks like."
Using Interface Builder to create his interfaces,
Desharnais says, "It's easier for me to design applications
that are beneficial to students. FlyLab is a good
example-the students get really excited." Desharnais is
currently adding more mutations to FlyLab and plans to have
a color version available by fall 1992.
For his Introduction to Ecology course, Desharnais created
Competition, a population ecology simulation application
that demonstrates conditions under which two competing
species may coexist.
"Many students don't realize biology involves mathematics
and statistics, and they become alarmed when they walk into
class and see formulas on the blackboard," he says. "I
designed Competition to give these students a way to see
the dynamics of the equations."
Competition is based on the classical Lotka-Volterra model
that describes the changes in numbers of two species by
three parameters: growth rates; carrying capacities (the
number of animals the environment can support); and
competition coefficients, defined as the percentage of
overlap in use of resources by the two species. Students
adjust the parameters and watch the species compete. The
simulation is depicted on a graph with an x/y plot, and a
curve represents the trajectory of the two-species
population as it changes over time.
In Seminar in Ecology, a graduate course, Desharnais has
his students use the Wingz graphic spreadsheet to program
examples of ecological data. Students learn how to compute
and interpret ecological statistics - for example,
estimating the size of a fish population from
mark-and-recapture data or measuring the species diversity
of plants from quadrat samples. Each student takes a turn
preparing a spreadsheet that contains all the statistical
formulas and graphics and uses NeXTmail to share it with
the class. The student leads a hands-on "guided tour"
through the spreadsheet using actual ecological data. All
the students then produce a second example on their own and
e-mail the spreadsheet to the instructor for grading.
"The students were really impressed with the power and ease
of use of the NeXT. All of them have requested permanent
accounts on the network, and some are now using the
spreadsheets for their master's thesis research," says
Desharnais.
In his own research, which focuses on nonlinear population
dynamics, Desharnais is using Interface Builder to develop
a model to simulate the growth of insect populations. His
research compares the effects of such nonlinear
interactions as cannibalism by adult-age insects on
immature insects. Desharnais uses different equations and
adds a variety of parameters to introduce randomness.
"This project is much easier to work on in the NeXT
computing environment," says Desharnais. "The big advantage
is being able to easily change the values of different
parameters without re-entering data, like I had to do on
other systems."
In addition, Desharnais is working with a high school
student, Alexandria Dominguez, who is part of the National
Science Foundation Young Scholars Program, to develop a
mathematical model on the NeXT machine that charts the
growth of mussels in intertidal zones. The function of the
model is to determine how tides and wave exposure affect
the growth rate and survival of mussels. Dominguez is
developing an interface for the application using Interface
Builder.
Physics, geology, and chemistry instructors are also using
the electronic classroom. Desharnais adds that faculty
members recently submitted another grant proposal to the
National Science Foundation to support future curriculum
development using NeXT technology.
"With the NeXT machines, we believe students will learn
science and math more effectively," he says. "And they will
be able to improve language skills in the classroom-an
exciting opportunity for teachers and students."
For more information, please contact:
Robert Desharnais
Assistant Professor of Biology
California State University, Los Angeles
5151 State University Drive
Los Angeles, CA 90032-8201
(213) 343-2056
bob@biol1next.calstatela.edu