Scientific Method

1
Scientific Method

• Bacon (1561-1626) and Descartes (1596-1650)
• were not scientists but did invent new habits of
  scientific thought
• scientific method as habits of disciplined
  creativity, careful observations, logical
  thinking analysis of observations
• way of seeking trends drawing generalizations
• Convinced governments of England France to form
  academies of science that still exist today
• Scientific way of thinking based on assumptions
  methods that are reliable, objective testable

2
Inductive Method

• Making observations until capable of drawing
  generalizations and making predictions
• anatomy is a product of inductive method
• Proof in science can not go past proved beyond
  reasonable doubt
• reliable methods of observation
• tested and confirmed repeatedly
• not falsified by any credible observation
• In science, all truth is tentative

3
Hypothetico-Deductive Method

• Physiological knowledge gained by this method
• Ask a question and formulate a hypothesis -- an
  educated possible answer
• Good hypothesis
• consistent with what is already known
• capable of being tested and falsified with
  certain evidence
• If nothing could prove it wrong, it is not a
  scientific belief
• Hypotheses are written as If-Then predictions
• modified and rewritten after testing

4
Experimental Design

• Sufficient sample size to prevent chance event
• Control group and treatment group receive the
  same treatment except for the variable being
  tested
• Prevention of psychosomatic effects
• use of placebo in control group
• Experimenter bias
• prevented with double-blind study
• Statistical testing to be sure the difference
  between groups was not random, but was due to
  variable being tested

5
Peer Review

• Critical evaluation by other experts in the field
• prior to funding
• verification and repeatability of results
• Ensures honesty, objectivity quality in science

6
Health Minister Manto Tshabalala-Msimang of South
Africa, known for putting vegetable remedies
ahead of anti-retrovirals, endorses Dr Matthias
Rath's vitamin treatments.
7
Dr. Rath and his cure for AIDS Mega Doses of
Vitamin C

• A doctor who worked with Nobel Prize winner Linus
  Pauling

• has taken the advocacy of vitamins into all-out
  war on the pharmaceutical companies
• Buys ad space in the NY Times, and fills them
  with editorials masked as facts
• Without getting confirmation of his studies is
  taking his cure to the people of Africa
• Problems Too much Vitamin C can lead to Diarrhea
  which can kill an AIDS patient.

8
Facts, Laws and Theories

• Scientific fact is information that can be
  independently verified by any trained person
• iron deficiency leads to anemia
• Law of nature is a description of the way matter
  and energy behave
• resulting from inductive reasoning repeated
  observations
• written as verbal statements or mathematical
  formulae
• Theory is a summary of conclusions drawn from
  observable facts
• it provides explanations and predictions
• sliding filament theory of muscle contraction

9
Logic is the anatomy of thought -John Locke

• Conditional arguments the basis of hypothesis
  forming. Two parts
• Part 1 If p then q
• P antecedent
• Q Consequent
• Part 2 allows us to draw conclusions
• If P happens then Q happens (Modus Ponens
• If Q did not happen, P did not happen (Modus
  Tollens)

10
There is a claim that lycopene, the reddish
substance in tomatoes and peppers, is of value in
protecting people from Alzheimer Disease. How
would you, as a scientist, go about
substantiating or refuting this suggestion?