Chemistry for Non-Science Majors: What Do They Need to Know, And How Do We
Teach It To Them?
Edward J. Baum
Chemistry Department
The
It is certain
that many of our non-science students will gain some control over our
scientific establishment and its activities in their professional capacities as
legislators, public administrators, jurists, business executives, and so
on. Most will give their opinions on
some scientific and technological issues as voters at the polls. What do we
want to communicate to these individuals while we have the opportunity? It seems that a chemistry course for
non-science majors should be about more than science literacy. In view of the important influence some of
these students may have eventually, such a course should help them develop the
critical reasoning skills needed by citizens living in a technological
society. Furthermore, our teaching
methods should make sense in view of our objectives.
We offer two courses in
chemistry for non-science majors at
The second chemistry course
is for honors students only and uses cooperative-learning techniques such as
guided-inquiry group projects and laboratories exclusively. It is offered in several sections of 24
students each. Both courses present
chemistry on a need-to-know basis in the context of societal issues. We are in the process of assessing the different
learning formats to determine the relative merits of cooperative learning techniques
in improving scientific literacy and in promoting critical reasoning skills. Here are some of our results.
Who are our non-science majors? At the start of each semester, all
students fill out extensive questionnaires that explore how much they remember
from the high school science courses they may have taken, their attitudes
toward science, and their preferred learning styles. Almost all students have had at least one science
course in high school. Many have studied
several subjects, including biology, chemistry, physics, and group
science. Most have a rough idea of the
goals of science and of the scientific method, although many confuse science
with applied science and engineering.
In general, the honors
students have better communication skills than the non-honors students. They read more, and they seem more motivated
to succeed. Also, they retain more facts
and ideas from their high school science classes. However, both honors and
non-honors students arrive with serious misconceptions based on prior
experience and education. For instance,
most see energy release in a chemical process as being like breaking an
egg. Break the egg…i.e. a chemical
bond…and out pours the energy. This
leads to great confusion in matters related to thermodynamics and chemical
bonding. Other common misconceptions about scientific issues have been
described (1).
There is little difference
between the attitudes of honors and non-honors students toward science. Many
say they don’t like to study science, and a significant number see little
professional value in understanding science.
Oddly, most claim to see personal advantages to being science literate.
The honors students claim to
learn best with a variety of teaching methods, whereas almost all of the non-honors
students claim to prefer listening to lectures. This may reflect a lack of
experience on the part of the non-honors students. Honors classes usually employ cooperative-learning
methods while the non-honors courses usually do not. It may also reflect unwillingness on the part
of some students to accept the responsibility for their own progress that goes
along with active learning. In any
event, the non-honors students require a period of familiarization before they
feel comfortable with cooperative learning.
I don’t think many of us
require our chemistry majors to memorize facts that can be found in reference
books, and we certainly would not require this of non-science majors. Nevertheless, it is amazing how many of our
non-science majors claim to have been asked to memorized the periodic table in
high school. Predictably, they derived
little benefit from this. Few can
remember the details. None understand
the table other than as a convenient collection of facts. For most students, it seems that high school
science is mainly about forgettable facts and has little to do with memorable
concepts. This is not what we want our
students to remember about chemistry.
What do our non-science majors need to know? Our
students will be called upon eventually to make decisions about technological
issues, and we should help them lay the groundwork for sound judgment in these
matters. For instance, students should
be helped to address the serious misconceptions that may lead to confusion in
understanding scientific concepts. While
our students have some appreciation of the scientific enterprise, they need to
appreciate the difference between science and engineering. This might help them understand the
adversarial nature of science and why there is almost never unanimity on scientific
issues.
Foremost, we should help our
students learn critical thinking skills.
If we want them to make careful and informed decisions about the technological
issues confronting them, they must learn to analyze complicated questions and
evaluate the risks and benefits of potential courses of action. Even science
majors would be best served with less rote memorization of facts and more
training in critical thinking.
How do we teach our students to correct their serious
misperceptions and learn critical thinking skills? It is estimated that about 80% of classroom time is
now spent in teacher talk (2). After
all, we were trained this way, so why not lecture to our students? Several serious shortcomings of the lecture
method have been identified (3,4). The lecture method assumes knowledge can be
efficiently transmitted directly from the teacher’s mind to the student’s
mind. This may be true if we are
communicating facts but not if we are asking students to understand
concepts.
For instance, a recent study
showed that the best lecturing at the finest institution may leave students
more confused about chemistry at the end of the semester than they were at the
beginning (5). One way of thinking about
this is that students may come to class with ideas that conflict with what they
will be asked by their instructor to understand and remember. If they are not challenged to test their counterproductive
beliefs and construct their own knowledge base, they can be left holding two
conflicting and confusing sets of ideas in mind, what the instructor wants them
to remember and what they actually believe to be true.
Lecturing takes no account of
a student’s preferred learning mode. Indeed, learning takes place, if at all,
after the lecture as our students try to make sense of their notes, solve
homework problems, and so on. This more
often than not means that students will focus on algorithms used to solve
specific kinds of problems. In the course of this rather impersonal and mechanical
process, students develop negative perceptions of science and fail to see the relevance
of the material presented to them (6,7).
Student’s learning styles are
likely to be different from the instructor’s and may be better addressed with cooperative-learning
methods (8). Indeed, we can all employ
more than one mode of problem solving (9), and we can allow for this best with such
methods. The problems mentioned so far
can be overcome by giving students the opportunity to challenge their misconceptions
and cooperate in the construction of their own knowledge base (10,11). The pedagogical
basis of cooperative learning has been reviewed in detail (12).
What are the results of our evaluation of cooperative
learning methods? At the end of the
2003 Winter semester, our students were tested on
their understanding of the same important scientific concepts that had been
explored in the preliminary tests administered at the beginning of the
semester. The students again filled out questionnaires concerning their
attitudes toward science. A few students
voluntarily submitted to follow-up interviews by faculty other than the course
instructor in which their understanding of the course material and their
attitudes were explored in depth.
We found that students who
attended lectures featuring supplemental cooperative-learning activities had a
50% lower drop rate and failure rate than students who attended lectures
only. The combined drop and failure rate
is normally 30%. Most students claimed
to find the active learning projects entertaining and helpful. Even students
who said that they do not ordinarily ask questions in lecture claimed to enjoy
the small group interaction. They liked
having time in class to think about their responses and work out answers with
their peers. Social interaction appears to enhance the educational experience
for the best as well as for the poorest non-honors students.
Students who attended
cooperative-learning sessions had much better scores on questions concerning
scientific concepts at the end of the semester than they did at the beginning. The
grade averages of non-honors students on concept questions were 21% on the
preliminary survey and 84% on the final exam.
Honors students grade averages showed comparable improvement. Follow-up interviews verified that students attending
cooperative-learning sessions did gain a good understanding of the scientific
concepts presented in class. This was
not the case for those students who attended lectures only. Many seem to have focused on algorithmic
problem solving instead of conceptual understanding. They often failed to see the relevance of
material presented and frequently complained when exam questions did not follow
the format of homework problems exactly. The students who attended cooperative-learning
sessions made no such complaints, indicating that they learned not to rely on
memorized problem-solving algorithms but gained some ability to use the
concepts underlying the questions. There was no difference between the honors
and non-honors students in this regard.
Only a small number of
students participated in our study in 2003, and the results described here are
preliminary. However, they are similar to
those obtained by other researchers (5,13). Cooperative-learning methods do help students
to learn scientific concepts and problem solving skills. Also, our students
claim that they help make their studies enjoyable, leaving them with a better
impression of science.
References:
1. See, for instance, Taber, K., Chemical misconceptions – prevention, diagnosis and cure. Royal Society of Chemistry,
2002.
2. Christenson et al., Education for Judgment,
3.
See for instance, Mazur E., Understanding
or Memorization: Are We Teaching the Right Thing?
4. Johnstone, A. H.,
Chemistry teaching – Science or Alchemy?
J. Chem. Educ.,
74: 262-268, 1997
5. Teichert, M., Promoting
understanding of Thermodynamics: The role of student explanation and
integration of ideas. Ph.D. Dissertation,
6. Tobias, S., They’re Not Dumb, They’re Different: Stalking the Second Tier,
Research Corp.,
7. Bodner, G. M.,
Constructivism: A Theory of Knowledge. J.
Chem. Educ., 63:
873-878, 1986.
8. Astin, A., What Matters in College: Four Critical years
Revisited, Jossey-Bass,
9.
10. Lawson, A. E., What Should Students Learn
About the Nature of Science and How Should We Teach It?,
Journal of College Science Teaching, 1999: 401-411.
11. Lawson, A. E., Science Teaching and the Development of
Thinking,
12. Spencer, J. N., New
Directions in Teaching Chemistry: A Philosophical and Pedagogical Basis, J. Chem. Educ.,
76, 566-569, 1999
13.. Farrell, J. J., Moog, R. S., and Spencer, J.
N., A Guided Inquiry General Chemistry Course. J Chem. Educ.,
76, 570-574, 1999.