Understanding the Nature of Science
Through College Introductory
Biology
Presentation at the 9th IHPST Conference, June 2007
University of Calgary
Calgary, AB Canada
Bridget Tuberty <bt65572@appstate.edu>
P.M. Dass <dasspm@appstate.edu>
Appalachian State University
Boone, NC USA
Why does understanding the
Nature of Science matter?
When asked about the
Theory of Evolution former
President Reagan replied,
“Well, it’s a theory a
scientific theory only…”
…25 years later
• According to the current President
Bush,
"Both sides ought to be properly taught . . .
so people can understand what the debate
is about,"
Primary Goal of Science
Education
Both the American Association for the
Advancement of Science (AAAS)
and the National Research Council
(NRC) agree that it should be
Scientific Literacy
What is Scientific Literacy?
“…the scientifically literate person is one
who is aware that science, mathematics,
and technology are interdependent
human enterprises with strengths and
limitations; understands key concepts
and principles of science; is familiar with
the natural world and recognizes both its
diversity and unity;
and uses scientific knowledge and
scientific ways of thinking for individual
and social purposes.”
AAAS, 1990, pg ix
Traditional Views of NOS
• Scientific claims are objective
because the theories and laws used
to make such claims are based on
empirical observation
• The testing of hypotheses is
controlled by a logical established
scientific method
• Science progresses linearly with the
ultimate goal of finding a
comprehensive theory
Contemporary view: The
assumptions and values of NOS
we want students to learn
1. Science demands and relies on
empirical evidence
2. In spite of commonalities there is no
single step-by-step scientific method
3. Scientific knowledge is tentative yet
durable
4. Laws and theories are related but
distinct kinds of scientific knowledge
5. Science is a highly creative
endeavor
Contemporary NOS cont.
6. Science has a subjective element
7. Science is a complex social
activity
8. Science and technology impact
each other, but they are not the
same
9. Science cannot provide complete
answers to all questions
McComas, 2004
Research Questions
1. What conceptions of the NOS do
college students bring to the BIO1101 course?
2. To what extent does the BIO-1101
for non-majors course influence
students’ conceptions of the
NOS?
Methods: Participants
• Fall 2005, BIO-1101
non-majors course
81 Freshman
163 Sophomores
45 Juniors
Instructor
Section
Enrolled
Total
M/F
Participated
Total
M/F
A
1
77
37/40
35
15/20
B
2
86
34/52
41
9/32
C
3
90
55/35
74
28/46
4
88
35/53
5
116
58/58
6
130
51/79
7
127
55/72
60
18/42
714
325/389
295
85/210
6 Seniors
D
E
Total
85
15/70
Quantitative Methods: Views on ScienceTechnology-Society (VOSTS)
Questionnaire
• Developed empirically by Aikenhead and Ryan
(1992)
• Validity has been proven in that it reflects students
viewpoints
• Researcher can select which questions to use ~ 25
out of the 118
• VOSTS has been successfully used with both high
school and university students and with teachers
• Response choices can be categorized allowing for
hypothesis testing with inferential statistics
Categorization of VOSTS
Responses
(Dass 2005; Rubba et al. 1996)
• Desirable (D): The choice
expresses a contemporary view
• Acceptable (A): The choice
expresses a view that includes a
number of legitimate points
• Undesirable (U): The choice
expresses a view that is
inappropriate or not legitimate
(doesn’t match any aspect of the
contemporary view)
Sign test analysis
• Response categories given numerical
values: D = 3, A = 2, U = 1
• Conversion to ordinal data allows for the
non-parametric Sign test to analyze
change from pre to post test
• Ho-the median difference in VOSTS item
response categories from pre-test to
post-test will not differ from 0 was tested
against the alternate hypothesis
• Ha-the median difference in VOSTS item
response categories from pre-test to
post-test will differ from 0
Qualitative Methods: Individual
Interviews to Corroborate VOSTS
Responses
• Selection of 11 VOSTS items
• All Instructors
• Students purposefully selected
based on quantitative findings:
26 students
• Approx. 30 minutes each
• Paid for Transcription
Qualitative Methods: Classroom
observations
•
Each Instructor’s class was videorecorded during:
1. Mendelian genetics
2. DNA structure
3. Microevolution
Resulted in 21 hours and 31 minutes
of lecture video which in turn
resulted in approximately 200
hours of transcription
Quantitative Results: College Students
Conceptions of NOS on Pre Course Survey
Question
1
13
14
15
16
17
18
19
20
21
22
23
24
25
2
3
4
5
6
7
8
9
10
11
12
U
6.3
15.2
19.9
23.8
13.3
81.5
8.3
9.7
15.5
17.4
9.5
49.3
45.7
51.9
5.0
20.3
5.4
30.6
3.7
2.3
31.1
42.5
17.8
17.7
14.7
A
59.1
25.0
36.5
16.1
54.1
12.4
90.7
34.3
57.6
43.8
90.5
0.0
12.0
37.0
24.3
10.3
73.5
23.6
66.0
12.6
9.8
31.1
58.7
40.3
40.7
D
34.6
59.8
43.5
60.1
32.7
6.0
1.0
56.0
26.9
38.8
0.0
50.7
42.3
11.1
70.4
69.3
21.1
45.8
30.3
85.0
59.1
26.4
23.5
42.0
44.7
NOS Component
Nature
of
Scientific
Knowledge
Characteristics of
Scientists
Social
Construction of
Scientific
Knowledge
Quantitative Results: To What Extent does BIO 1101
Influence Student Conceptions of NOS
Question 16: Even when scientific investigations are
done correctly, the knowledge that scientists
discover from those investigations may change in
the future.
Incorporates:
(3) Scientific knowledge is tentative
but durable
Even when scientific investigations are done correctly, the
knowledge
that scientists
from(+)those investigations
may
Instructor
Negativediscover
(-)
Positive
Ties
p
differences
differences
change in the
future.
A
11
Desirable Conception
Choice:13
B
C
19
B. Because the
old
knowledge
is
D
24reinterpreted
facts can change.
E
18
Total
85
7
17
9
21
12
39
in17light of new discoveries.
43
14
30
59
150
0.481
0.523
0.281
Scientific
0.349
0.596
0.037
Percentage (%) of Students
*No instructor Desirable
80
70
60
50
Pre
40
Post
30
20
10
0
U
A
Category Conception
D
Instructor B
100
Percentage (%) of
Students
Percentage (%) of
Students
Instrtuctor A
80
60
Pre
40
Post
20
0
U
A
80
60
Pre
40
Post
20
0
D
U
Category Conception
A
Category Conception
Instructor D
Percentage (%) of
Students
60
50
40
30
20
10
0
Pre
Post
A
80
60
Pre
40
Post
20
0
U
D
A
Category Conception
Category Conception
Instructor E
Percentage (%) of
Students
Percentage (%) of
Students
Instructor C
U
D
60
50
40
30
20
10
0
Pre
Post
U
A
Category Conception
D
D
Student comments on the tentative
nature of scientific knowledge
• “Yes, we talked a lot about how things were
always changing and how even though multiple
experiments could prove a certain theory-just
one could disprove it.” from Instructor C’s class
• “…knowledge is always changing, the world is
flat the world is round. In Instructor C’s class,
he/she was always like; scientists are always out
to disprove each other, because that’s how
science gets better.”
Question 17: Scientific ideas develop from
hypotheses to theories, and finally, if they are
good enough, to being scientific laws. Your
position basically:
Incorporates:
(4) Laws and theories are related
but distinct kinds of scientific
knowledge
Instructor
Negative (-)
Positive (+)
Ties
p
differencesfrom hypotheses
differences
Scientific ideas develop
to theories, and finally,
A they are good
1 enough, to2 being scientific
32
1.000
laws.
B
10
7
26
0.629
C
12
8
52
0.503
Desirable Conception
Choices:
D
9
9
68
1.000
E. Theories can’t
become
laws
because
they
both
are
different
types
of
ideas.
Laws
E
10
7
45
0.629
describeTotal
things in general. 42
Theories explain 33
these laws. However,
with 0.356
supporting
223
evidence, hypotheses can become theories (explanations) or laws (descriptions).
Percentage (%) of Students
*Instructor D only Desirable
90
80
70
60
50
40
30
20
10
0
Pre
Post
U
A
Conception Category
D
if
Instructor B discussing Mendelian
genetics during lecture
• “So the 1st law or the 1st theory that Mendel came
up with he called the Law of Segregation …so now
through his experiments so far we’ve done a
monohybrid cross and a test cross both to support
his Theory of Segregation.”
• “So from the data he collected he formed a theory,
Theory of Segregation, now people call it the Law of
Segregation of alleles…”
Student Interviews About Hypotheses,
Theories, and Laws (oh, my)
• “I’m going to lean more to how many times its been proven. If it’s been
proven so many times and hasn’t been able to be disproven then, I
mean, it becomes a law.” Instructor A’s student
• “I don’t think that it should, uhm, because like a theory you know isn’t
100% true and I don’t know, I don’t know, everything that we’re taught in
science is a theory and they’ve been teaching it for so long and it just
seems like that if that were true it would have already become a law.”
Instructor B’s student
• “…I think like, with hypotheses they have to be tested a lot, like
experimented and experimented and have all of the supporting evidence
gathered together in order to make it a theory so after its been proven
true for so many times then I think yes it’s a hierarchy but once it’s
proven by experiments it’s a theory and then once that theory becomes
absolutely true then it’s a law.”
Instructor E’s student
Discussion of Theory in Instructor C’s Lecture
on Microevolution
• “Remember how we spoke about theories aren’t
hypotheses, they’re basically these unifying
principles that are supported by everything that we
know about the field of biology and so that’s why
biologists get really irate when people want to not
allow it to be taught because it’s basically the fiber
that holds everything that we know about biology
together and so that’s why it’s really important and
actually why I’m teaching it right at the very end of
the semester is because we will be able to see that
everything that we learned this semester goes into
supporting this theory.”
Student Interviews About Hypotheses,
Theories, and Laws (oh, my)
• “Well, you always hear that the Theory of Evolution is
just a theory, but when scientists think of the word
theory it’s as if theory means law to the scientist and
theory is hypothesis to the lay person. Like, oh it’s
just a theory, like it’s just something like a
hypothesis, but scientific theory is much more
concrete with strong evidence and it’s just a theory,
laws are supposed to be 100% concrete
stable…theories you can change around, I don’t
know, I’m not really sure anymore.”
Instructor C’s student
Question 18: Explicitly addresses: (2) in spite of
commonalities there is no single step-by-step scientific
method
When scientists investigate, it is said that they follow the scientific method. The scientific method is:
Your position, basically: (Please read from A to M, and then choose one.)
U/1 A.
A/2 B.
A/2 C.
A/2 D.
A/2 E.
A/2 F.
A/2 G.
A/2 H.
A/2 I.
D/3 J.
U/1 K.
U/1 L.
U/1 M.
the lab procedures or techniques; often written in a book or journal, and usually by a scientist.
recording your results carefully.
controlling experimental variables carefully, leaving no room for interpretation.
getting facts, theories or hypotheses efficiently.
testing and retesting – proving something true or false in a valid way.
postulating a theory then creating an experiment to prove it.
questioning, hypothesizing, collecting data and concluding.
a logical and widely accepted approach to problem solving.
an attitude that guides scientists in their work.
Considering what scientists actually do, there is really no such thing as the scientific method.
I don’t understand.
I don’t know enough about this subject to make a choice.
None of these choices fits my basic viewpoint.
Instructor
Negative (-)
differences
3
7
18
10
5
43
A
B
C
D
E
Total
Positive (+)
differences
1
3
4
5
8
21
Ties
p
31
33
52
71
50
237
0.625
0.344
0.004
0.302
0.581
0.009
Percentage (%) of Students
*All Instructors Acceptable except D Undesirable
100
90
80
70
60
50
40
30
20
10
0
Pre
Post
U
A
Conception Category
D
Instructor B
120
100
80
60
40
20
0
Percentage (%) of
Students
Percentage (%) of
Students
Instructor A
Pre
Post
U
A
100
80
Pre
60
40
Post
20
0
U
D
Category Conception
A
Category Conception
Instructor D
80
60
Percentage (%) of
Students
100
Pre
40
20
Post
0
A
100
80
Pre
60
40
Post
20
0
D
U
A
Category Conception
Category Conception
Instructor E
Percentage (%) of
Students
Percentage (%) of
Students
Instructor C
U
D
100
80
60
Pre
40
20
0
Post
U
A
Category Conception
D
D
Portrayals of the Scientific Method from
Mendelian Genetics Lectures
• Instructor C: “…remember when we spoke about
the scientific method the 1st day of class? So, uhm,
you remember how we said you make an
observation, form a hypothesis, do an experiment
that gets results, which means you ask more
questions, make more hypotheses and it just kind of
becomes this expansion of knowledge type of
thing…”
• Instructor E: “Good, okay, nice hypothesis, nice
explanation, you’ve got to test it, it’s got to be
tested, you’ve got to use the hypothesis to set up
another experiment, predicting the results from this,
you know using, using this hypothesis.”
The scientific method as a series of steps
perpetuates the view that theories are easy to
dismiss
• Dagher and BouJaoude, (2005) found that students felt the
theory of evolution did not follow the scientific method
therefore it was lacking evidence to make it credible
• Sandoval and Morrison (2002) concluded that the simplistic
linear model of the scientific method promotes the idea of
theories as proven hypotheses
• Compound this with the hierarchy of scientific ideas, or the
belief that theories are not as “proven” or valid as a law and it
is easy to see how misconceptions about science affect
people and their reasoning on the theory of evolution
How this could be perpetuated by the language used
in lecture
• “…I’d also like to give lots of examples of how we see this
today because being scientists, without evidences, without
experimental proof this is all still trajectory, okay.”
• “Now when you look at something and make an observation
and then attempt to come up with a conclusion we call this
pattern versus process. We see a pattern we try to make a
conclusion about it, however we didn’t do any sort of
experiment to get our conclusion, okay, this is not science
that is simply making an observation. Mendel had enough
scientific background to know that he needs to set up an
experiment in a logical manner and attack this question with
data not just with observations.”
Instructor B
What students said when asked where they
had gotten their views on scientific ideas and
the scientific method
• “I mean going all the way back to middle school and high
school. A scientific law is much more above a theory.” A
• “…it’s the way my teachers have always taught it since, you
know I actually started paying attention in science classes like
9th grade you know, you see, you test your hypotheses and
that becomes a theory that you can base other things off of
and then we learned about laws which are proven and
unquestionable.” D
• “Uhm, when you’re in the 7th grade and you learn the scientific
method that is exactly what you learn and you experiment and
you go through those 4 well its really 7 steps.” A
• “It has been pounded into my mind since the start of scientific
education…steps, concrete one after another.” C
Explicit discussions can influence students
Students that selected J on post course survey,
Bridget: “Has there been anything in particular that influenced
you to say that?”
Student: “I think I remember a professor having a little spiel
about there being no actual scientific method.”
Bridget: “Was that in 1101?”
Student: “Possibly, yes it was in college. I think that the
scientific method as its presented in textbooks can be an
idea of what science tries to do, the ideals, I think in an
actual experiment you don’t have to the steps, you don’t
follow the steps…in high school you had this whole little
outline you know you start, you question things, you make
hypotheses, and you develop an experiment and you
experiment and if it supports your hypothesis then your
hypothesis becomes your theory, if it doesn’t support then
you alter the hypothesis and you go through the steps all
over again.” D
Response choice
a
b
Pre
c
d
e
f
g
h
i
j
l
m
Total
• 40% of students selected the
step-by-step method on posttest compared to 44% on pretest
• However more students
selected ‘U’ choice A (lab
procedures and techniques written in a lab
book or journal usually by a scientist)
Percentage (%) of Students
100
80
60
Pre
40
Post
20
0
-20
U
A
Conception Category
p=0.009
D
Response choice
a
b
c
Post
d
e
f
g
h
i
j
k
l
m
Total
Frequency
19
12
12
17
32
8
132
57
3
3
3
3
301
Percent
6.3
4.0
4.0
5.6
10.6
2.7
43.9
18.9
1.0
1.0
1.0
1.0
100.0
Frequency
34
11
22
16
31
6
121
44
4
1
2
2
7
301
Percent
11.3
3.7
7.3
5.3
10.3
2.0
40.2
14.6
1.3
.3
.7
.7
2.3
100.0
Conclusions
• Students still hold misconceptions of NOS
• The 1101 course is currently taught as a
historical introductory course and in most
cases is not significantly influencing
students toward contemporary conceptions
of NOS
• Abd-El-Khalick & Lederman (2000);
Schwartz & Lederman (2002) found that
reiterations of history not enough to
influence students and that explicit
discussion about NOS is needed
Why improving student
conceptions of NOS matters
• Student views about science
determines how they learn science
(Edmondson & Novak, 1993; Songer & Linn, 1991)
– When students believe that scientists
simply add facts to a body of
knowledge as opposed to deliberating
between different viewpoints they are
more likely to memorize facts as a
way of learning and are therefore less
likely to integrate science with their
own viewpoints
NOS misconceptions can affect
students’ abilities to deal with scientific
controversies
• People who do not incorporate
scientific knowledge with personal
knowledge lack reflective reasoning
skills and are not able to deliberate
between different viewpoints and
evidence resulting in their being
more likely to accept the views of
authoritative figures without really
developing and understanding of
those views (Lawson & Weser, 1990)
The good news
• Students who take college level science
course are more scientifically literate and
more comfortable with science (Miller, 2004)
• Although certain conceptions are more
ingrained than others we can still
influence college students’ conceptions
(Edmondson & Novak, 1993; Lord & Marino, 1993)
Implications
• More emphasis of NOS and science
content for science education programs
(Brickhouse et. al., 2000; Swartz & Lederman, 2002)
• If the general education goal is to improve
scientific literacy then curriculum reform
towards a more outcome assessment
based program away from a content driven
course is a good idea
Questions?