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Increasingly, chemistry instructors, especially in two-year colleges,
find themselves teaching classes where there is great disparity in
the academic preparation of the students and where even those students
with good mathematics and basic science backgrounds have poor English
language and communication skills. This project explores the use of
technological innovations to facilitate learning in introductory chemistry
courses by those with a poor academic background, while also challenging
those prepared to master the curriculum. An additional objective is
to improve the communication skills of all students. Material is presented
visually and in as engaging a fashion as possible, students are provided
ready access to relevant information about the course content in ways
that are adapted to their individual learning styles, and collaborative
learning is encouraged, especially among those who work and live at
a distance from campus. The chief tactics employed are:
- Development of software that can be customized
to meet the varying needs of individual students, courses, and instructors.
- Use of simulations that, while not replacing laboratory
bench experiments, allow students to practice important laboratory
techniques and observe the physical behavior of chemical systems.
- Use of software that allows students to explore the
molecular basis of chemical phenomena.
- Use of software that allows students to display and
analyze data in ways that facilitate drawing general conclusions about
the quantitative relationships between observable properties.
- Use of the computer as a communications device.
The ability to customize software is important in adapting to
different learning styles and in encouraging students to learn by
discovery. For example, TitrationLab was developed so that the material
may merely be presented empirically or in ways in which the principles
of equilibrium are demonstrated. At the advanced level, automatically
generated titration curves are used to determine acid/base dissociation
constants. Several curves may be superimposed to enable visual comparison
and emphasize the effect of acid/base strength on overall curve shape.
At the simplest level, the user determines the equivalents of an unknown
acid or base using an indicator, and titration curves are not shown.
When an inappropriate indicator is chosen and the student discovers,
for example, that a color change occurs even when significantly less
than the equivalent amount of titrant is added, this becomes a point
of departure for explaining the chemical functioning of an indicator
and how to select the proper one for a particular analysis. The student
interfaces with TitrationLab through interactive representations
of traditional laboratory apparatus displayed on the screen so as
to simulate actual laboratory manipulations, and the student is made
aware of the consequences of mistakes common among novices in the
laboratory, such as forgetting to add the indicator, allowing the
buret contents to fall below the zero level, etc.
Comprehension of abstract concepts is facilitated by the use of computer-
generated displays. It'sAGas! is a newly developed hard-sphere
simulation of the behavior of gas molecules demonstrating the basic
principles of the kinetic molecular theory of gases. The concept of
pressure as the rate of component particle collisions is made more
vivid by having sound accompany collisions. The effect of changing
conditions such as temperature on molecular properties, such as velocity,
or of changing container size on the frequency of particle collisions
is vividly illustrated. RasMol, shareware by Roger Sayle, allows
the user to manipulate the computer representation of a molecule with
intuitive mouse commands in a way that facilitates exploration of
concepts such as the relationship between symmetry and dipole moment.
The multitasking capability of the operating system used in the project
allows simultaneous execution of software like RasMol and related
applications such as one on VSEPR.
Computer-fitting of smooth curves to experimental data was a new experience
for many students. In the second semester general chemistry course,
students determined the equivalence points from the first derivative
of a curve fit to their experimental measurements. Points of inflection,
maxima, minima, and other mathematical parameters now had a real meaning
in terms of observable properties of the physical systems being studied,
and many students voiced satisfaction in applying what they had learned
in mathematics classes to analyzing data collected in the science
laboratory.
A commercial spreadsheet with a scripting language is used for data
analysis. Students enter their experimental data and calculated results.
The script indicates if their result is correct within reasonable
limits of error but does not perform the calculations for them. Most
students opt to use this application even though it is not required.
A bulletin board system (ChemistryBBS) with a graphical user
interface has been created in which students post questions on course
material and other students or faculty post answers or suggestions.
ChemistryBBS encourages participation by those who do not speak
up in class as well as by those whose spoken English is imperfect.
Students use e-mail to hand in homework and laboratory reports. They
particularly enjoy the ease with which graphics can be incorporated
into text documents, and many students produce professional looking
reports.
Other courseware in various stages of development include Dimensions
(dimensional analysis), MindYourSigFigs (use of significant
figures in measurements), What'sInAName (inorganic nomenclature),
PeriodicTable (an interactive handbook of periodic properties
of the elements), RedoxReactions, ElectrochemicalCells, and
Carbon-13NMR. A commercial application that captures screen
images and sound is used to develop custom lesson modules adapted
to the learning styles of individual students and made available over
the computer network. Use of network-based applications will be greatly
expanded in the immediate future with adoption of CAPA (Computer-Assisted
Personalized Assignment), a software tool developed by Michigan State
University for implementing a computer-assisted personalized approach
to homework assignments, quizzes, and even examinations.
The NEXTSTEP operating system used exclusively during this initial
phase of the project is a UNIX-based software development environment
that is extremely developer- and user-friendly and has excellent multitasking,
multimedia, e-mail, and communications capabilities. It operates on
a local area network consisting of six 486 and Pentium workstations,
a printer, and a scanner. A recent grant from the Ralph M. Parsons
Foundation will add 10 workstations and software to accommodate additional
students and courses. The new workstations will have both Windows
NT and the NEXTSTEP operating system installed, as applications developed
under the latter are readily transported to the former through use
of OPENSTEP objects.
Acknowledgment
The author is grateful to the National Science Foundation Division
of Undergraduate Education for support of this project through Grant
No. DUE9350851 from the Instrumentation and Laboratory Improvement
Program and Grant No. DUE9354531 from the Course and Curriculum Development
Program.
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