The document discusses the key assumptions and methods of science. It explains that science is based on empirical observation and testing of hypotheses, but also has limitations. The assumptions of science include empiricism, objectivity, materialism, predictability, and the idea that the universe has a unified structure. However, science is a human system and new evidence sometimes challenges existing theories, leading to paradigm shifts in scientific thought. The document emphasizes the importance of critically evaluating scientific claims and being aware of the strengths and weaknesses of scientific reasoning.

1. SCIENCE
The aim of this tutorial is to help you learn to
identify and evaluate scientific methods and
assumptions.

2. What is this scientist thinking as
she evaluates the glass flask?
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3. What is science?
Science rests upon reasoning that moves from
observable, measurable facts, usually called data, to
testable explanations for these facts. Scientists discover,
observe, and collect facts in a systematic manner to
explain data relationships. They then link these
relationships through explanatory devices such as
hypotheses. Modern science has a profound impact on our
lives, and because it is so pervasive, we tend to perceive it
as the natural method for obtaining knowledge about the
world. However, we must recognize and evaluate the
assumptions underlying science to ensure what we are
learning is accurate and credible.
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4. Copernicus observed that the Earth
revolves around the sun, and not vice versa.
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5. Assumptions underlying science
Science is the primary way Western culture perceives and
interprets reality. However, it is important to keep in mind
that science is a system created by humans and, as such,
is based on a particular set of assumptions. These
assumptions include empiricism, objectivity, materialism,
predictability, and unity.
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6. Empiricism, objectivity, materialism,
predictability, and unity
 Empiricism—Sense experience is the source of truth.
 Objectivity—We can study the physical world without
bias.
 Materialism—Everything in the universe is made up of
physical matter.
 Predictability—The universe is composed of
interconnected causal relationships.
 Unity—The universe has an underlying, unified dynamic
structure.
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7. Hot or Not?
Is science the best tool for
learning about the world?
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8. Limitations of science
 Despite its obvious strengths, scientific reasoning has
some limitations. Empiricism and the use of sense
experience limits science to observable, shared
phenomena. Additionally, the basis of science, the
existence of the physical world, cannot be empirically
proven. Furthermore, quantum physics challenges the
idea that reality is ultimately predictable and material,
and that objective observation is even possible.
 As critical thinkers, it is important to keep both the
strengths and limitations of scientific reasoning in mind.
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9. Our brain’s tendency to impose order on
random data contributed to the belief that
there were canals on Mars.
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10. The religious belief that humans are a
special creation is one of the underlying
assumptions of modern science.
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11. The scientific method
 The scientific method is the basis for generating
scientific knowledge. It involves a series of steps.
 Identify the problem.
 Develop an initial hypothesis.
 Gather additional information and refine the
hypothesis.
 Test the hypothesis.
 Evaluate the hypothesis based on the results of
testing or experimentation.
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12. Differences among Galapagos Island
finch beaks, as illustrated by Darwin
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13. Margaret Mead’s attachment to her hypothesis
and reliance on anecdotal evidence biased the
way she gathered her information.
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14. Twin studies
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15. Evaluating a scientific hypothesis
 When evaluating a scientific hypothesis, the following
criteria are appropriate:
 Is it relevant to the problem under investigation?
 Is it consistent with well-established theories?
 Is it the simplest explanation for the problem?
 Does it provide a testable and falsifiable explanation
of the problem?
 Can it be used to predict the outcome of similar
events?
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16. Marie Curie
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17. Albert Einstein
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18. The hypothesis “all swans are white” was falsifiable.
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19. Distinguishing between science and
pseudoscience
Pseudoscience is a body of explanations or hypotheses
that, in an attempt to gain legitimacy, masquerades as
science. Unlike science, which uses systematic
observation, reasoning, and testing, pseudoscience is
based on emotional appeals, superstition, and rhetoric.
Astrology is an example of pseudoscience. Pseudoscience
takes advantage of cognitive errors in our thinking, and is
often used to persuade people, particularly the young, as a
means to gain money or political support.
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20. Nostradamus’s prophecies tended to be so vague that
they could only be “proven” after they had happened.
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21. Research methodology
Research methodology is a systematic approach to
gathering and analyzing information based on established
scientific procedures and techniques. One of these
methodologies is experimentation. Three common types of
experimentation are field experiments, controlled
experiments, and single group (pretest-posttest)
experiments. These experiments include elements such as
independent variables, dependent variables, and
confounding variables, and all use experimental material,
the group or class of objects or subjects under study.
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22. Hot or Not?
Are field experiments real scientific
experiments?
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23. Jane Goodall used observation as a research method.
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24. Mice or other lab animals are often
used as experimental subjects.
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25. Evaluating experimental designs
 Regardless of which type of experiment design is used,
common evaluation criteria can be applied to test the validity
of the experiment and its results. Well-designed experiments
use the following criteria:
 Unbiased—The experiment has checks or controls to eliminate both
subject and experimenter bias.
 Measurement—The measurements used are appropriate and
reliable as well as accurate and precise.
 Replicable—The experiment can be reproduced by other scientists.
 Generality—The experimental results can be generalized to the
population under study.
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26. Ethical concerns in science
Although scientific experiments may be well designed
and produce significant results, they may be inappropriate
due to their violation of moral and ethical principles and
guidelines. Ethical considerations of informed consent,
rights, and nonmaleficence (no harm) are particularly
important when dealing with human subjects. During World
War II, Nazi doctors performed unethical experiments on
Jews, prisoners of war, and other prisoners. These
activities have also occurred in the United States, such
as in the Tuskegee study.
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27. Hot or Not?
Should pregnant women, or
women who might become
pregnant, be allowed to participate
in drug tests?
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28. Hot or Not?
Is it desirable, or even possible, for
science to become value-neutral?
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29. Thomas Kuhn and scientific paradigms
In his work The Structure of Scientific Revolutions (1962),
American physicist and science historian Thomas Kuhn
(1922-1996) challenged the idea that science is
progressive and objective. Instead he argued that science,
like other human enterprises, is a social construct—
a product of its society. As such, it is biased by social
expectations and professional norms that determine what
is acceptable in terms of hypotheses and experimentation.
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30. Scientific revolutions and paradigm
shifts
Kuhn argued in favor of three key concepts: normal
science, paradigms, and scientific revolutions. Normal
science refers to “research based upon one or more past
achievements,” while paradigms, building on normal
science, provide an accepted view of the world. A
scientific revolution, or paradigm shift, occurs when a
new scientific theory is developed to replace a problematic
paradigm. Einstein’s theory of relativity is an example of a
paradigm shift.
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31. It took many years for continental-drift theory
to be accepted by most people in the field.
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32. Conclusions
Science and scientific thinking has generated enormous
benefit to humanity. However, as critical thinkers we must
be aware of its limitations, the temptations of
pseudoscience, and the possibilities of other explanations
for phenomena. We must use evaluative criteria when
considering scientific reasoning, and recognize that new
ideas may hold answers to questions that existing
paradigms cannot resolve.
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33. Evolution versus intelligent design
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