The Scientific Method

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The Scientific Method

• Mr. Knowles
• Anatomy and Physiology
• Liberty Senior High School

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Early Anatomists

• Hippocrates- Greek philosopher and physician, 400
  B.C.
• Hippocratic Oath
• Four Humours of the body.
• Observations, little Experimentation

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Greek and Roman Surgical Instruments
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Early Black Bag
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Claudius Galenus (Galen)

• Roman anatomist during the 1st Century.
• Described the human anatomy in detail.
• Little understanding of physiology.

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Galens Office
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Galens Specimens
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Vesalius

• 16th Century anatomist who provided exquisite
  detail of systems.
• Experimentation with domestic animals. To
  determine function.
• Assumed Galen to be correct not questioned.

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Vesalius at Work!
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William Harvey

• 17th Century English anatomist who questioned
  some of Galens conclusions.
• Determined how the CV system worked in 1628
  publication.
• Used experimentation to prove CV function.

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The Scientific Method

• An empirical way of explaining phenomena in the
  world.

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With what does all good science research begin?

• A Question!
• 21 Questions to Conclusions!

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Make a Concept Map to Relate the Following Terms

• Theory
• Hypothesis
• Principle
• Law

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See My Concept Map

• Click to View

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(No Transcript)
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Some Definitions

• Law or Fact- a confirmed observation (direct/or
  indirect).
• Hypothesis- a testable prediction, based on prior
  knowledge and experience.
• Theory- a unifying explanation of several facts
  a working model.
• Principle- who knows?

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Based on our discussion

• What would you call the idea of Spontaneous
  Generation?
• Germ Theory?

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The Role of Hypotheses in Inquiry

• In science, a hypothesis
• Is a tentative answer to a well-framed question,
  an explanation on trial
• Makes predictions that can be tested

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Hypothesis

• Comes from an observation --- question or a
  problem.
• It is a Testable Prediction (Maybe True or
  False).
• Written as an If __I.V.___, then _D.V.____
  statement.

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• Hypotheses in Everyday Problems

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Deduction The Ifthen Logic of
Hypothesis-Based Science

• In deductive reasoning
• The logic flows from the general to the specific.
• If a hypothesis is correct
• Then we can expect a particular outcome.

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Hypothetico-Deductive Reasoning

• Actually written as If and thentherefore.
• If (your hypothesis) and (planned experiment),
  then (expected results)therefore(conclusion).

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Hypothesis must be...

• Testable (Falsifiable) (ex. Absolute Zero---
  Molecular Motion Stops)
• Unbiased (ex. Cancer statistics in North America
  Utah vs, D.C.)
• Repeatable (ex. Cold Fusion, University of Utah
  experiment)

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Pons and Fleischmann, University of Utah, 1989
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An Unbiased Hypothesis?

• Research testing the hypothesis that cell
  phones-- brain tumors.
• Who funds this work?
• Motorola- the number one manufacturer of cell
  phones in U.S.

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Writing a Hypothesis
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Dangerous Breast Implants?

• Do breast implants cause connective tissue
  disease?
• How would you write a hypothesis?

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Whats wrong with this?
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The Scientific Method
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Designing Controlled Experiments

• Experiments must be designed to test
• The effect of one variable by testing control
  groups and experimental groups in a way that
  cancels the effects of unwanted variables.

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A Case Study in Scientific Inquiry Investigating
Mimicry in Snake Populations

• In mimicry
• A harmless species resembles a harmful species

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• In this case study
• Mimicry in king snakes is examined
• The hypothesis predicts that predators in
  noncoral snake areas will attack king snakes
  more frequently than will predators that live
  where coral snakes are present

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Field Experiments with Artificial Snakes

• To test this mimicry hypothesis
• Researchers made hundreds of artificial snakes,
  an experimental group resembling king snakes and
  a control group of plain brown snakes

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• After a given period of time
• The researchers collected data that fit a key
  prediction

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If a hypothesis meets all criteria, then...

• Test hypothesis by experimentation.
• After repeated testing, a hypothesis may support
  a Scientific Theory.

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A Theory must ...

• Describe a real phenomenon (always true).
• Make accurate predictions about the world.
• Be dynamic, able to be refined or updated.

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Model Building in Science

• Models of ideas, structures, and processes
• Help us understand scientific phenomena and make
  predictions

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What is the difference between a fact and a
theory?

• The Theory of Gravity
• Ex. Newton and Einstein- both contributed to
  the theory.
• new information---revision of theory.

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Scientific Method

• Problem
• Hypothesis
• Materials
• Procedure
• 1. Number steps
• 2. Control Group/Experimental group
• 3. Constants

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• Data/Results
• 1. Title
• 2. Label axis x-axis - IV
• y-axis - DV
• Conclusions
• (including discussion of errors)