Understanding the Nature of Science Through College Introductory Biology

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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 ltbt65572_at_appstate.edugt
• P.M. Dass ltdasspm_at_appstate.edugt
• Appalachian State University
• Boone, NC USA

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Why does understanding the Nature of Science
matter?
When asked about the Theory of Evolution former
President Reagan replied,
Well, its a theory a scientific theory only
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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,"

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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
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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
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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

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Contemporary view The assumptions and values of
NOS we want students to learn

• Science demands and relies on empirical evidence
• In spite of commonalities there is no single
  step-by-step scientific method
• Scientific knowledge is tentative yet durable
• Laws and theories are related but distinct kinds
  of scientific knowledge
• Science is a highly creative endeavor

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Contemporary NOS cont.

• Science has a subjective element
• Science is a complex social activity
• Science and technology impact each other, but
  they are not the same
• Science cannot provide complete answers to all
  questions

McComas, 2004
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Research Questions

• What conceptions of the NOS do college students
  bring to the BIO-1101 course?
• To what extent does the BIO-1101 for non-majors
  course influence students conceptions of the
  NOS?

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Methods Participants

• Fall 2005, BIO-1101 non-majors course

81 Freshman 163 Sophomores 45 Juniors 6 Seniors
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Quantitative Methods Views on Science-Technology-
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

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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 (doesnt
  match any aspect of the contemporary view)

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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

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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

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Qualitative Methods Classroom observations

• Each Instructors class was video-recorded
  during
• Mendelian genetics
• DNA structure
• Microevolution
• Resulted in 21 hours and 31 minutes of lecture
  video which in turn resulted in approximately 200
  hours of transcription

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Quantitative Results College Students
Conceptions of NOS on Pre Course Survey
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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

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Even when scientific investigations are done
correctly, the knowledge that scientists discover
from those investigations may change in the
future.
Desirable Conception Choice B. Because the old
knowledge is reinterpreted in light of new
discoveries. Scientific facts can change.
No instructor Desirable
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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 Cs class
• knowledge is always changing, the world is flat
  the world is round. In Instructor Cs class,
  he/she was always like scientists are always out
  to disprove each other, because thats how
  science gets better.

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• 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

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Scientific ideas develop from hypotheses to
theories, and finally, if they are good enough,
to being scientific laws.

• Desirable Conception Choices
• Theories cant become laws because they both are
  different types of ideas. Laws describe things
  in general. Theories explain these laws.
  However, with supporting evidence, hypotheses can
  become theories (explanations) or laws
  (descriptions).

Instructor D only Desirable
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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 weve 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

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Student Interviews About Hypotheses, Theories,
and Laws (oh, my)

• Im going to lean more to how many times its
  been proven. If its been proven so many times
  and hasnt been able to be disproven then, I
  mean, it becomes a law.
• I dont think that it should, uhm, because like
  a theory you know isnt 100 true and I dont
  know, I dont know, everything that were taught
  in science is a theory and theyve been teaching
  it for so long and it just seems like that if
  that were true it would have already become a
  law.
• 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 its a hierarchy but once its proven
  by experiments its a theory and then once that
  theory becomes absolutely true then its a law.

Instructor As student
Instructor Bs student
Instructor Es student
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Discussion of Theory in Instructor Cs Lecture on
Microevolution

• Remember how we spoke about theories arent
  hypotheses, theyre basically these unifying
  principles that are supported by everything that
  we know about the field of biology and so thats
  why biologists get really irate when people want
  to not allow it to be taught because its
  basically the fiber that holds everything that we
  know about biology together and so thats why
  its really important and actually why Im
  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.

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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 its as if theory means
  law to the scientist and theory is hypothesis to
  the lay person. Like, oh its just a theory,
  like its just something like a hypothesis, but
  scientific theory is much more concrete with
  strong evidence and its just a theory, laws are
  supposed to be 100 concrete stabletheories you
  can change around, I dont know, Im not really
  sure anymore.

Instructor Cs student
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Question 18 Explicitly addresses (2) in spite
of commonalities there is no single step-by-step
scientific method
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All Instructors Acceptable except D Undesirable
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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, youve got to test it, its got to
  be tested, youve got to use the hypothesis to
  set up another experiment, predicting the results
  from this, you know using, using this hypothesis.

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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

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How this could be perpetuated by the language
used in lecture

• Id 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 didnt 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
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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
• its 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 youre 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 educationsteps, concrete one after
  another. C

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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 dont have to the steps, you dont
  follow the stepsin 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 doesnt support then
  you alter the hypothesis and you go through the
  steps all over again. D

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• 40 of students selected the step-by-step method
  on post-test compared to 44 on pre-test
• However more students selected U choice A (lab
  procedures and techniques written in a lab book
  or journal usually by a scientist)

Pre
Post
p0.009
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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

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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

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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)

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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)

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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

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Questions?