Post on 22-Feb-2016
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Scientific Method (Inquiry)
What is the scientific method…..
?The scientific method is a ______
for answering questions.process
What is Science?
or
Here are a few statements to test your current
understanding of science!
Science actually attempts to disprove ideas (hypotheses).Science is limited strictly to solving problems about the physical and natural world.
Science can prove anything, solve any problem or answer any
question.True or False?
False
Any study done carefully and based on observation is scientific.
Science must follow certain rules. The rules of science make the scientific process as objective as is possible.
Objective = Not influenced by feelings, interests and prejudices; UNBIASED
vs.
Subjective = Influenced by feelings, interests and prejudices; BIASED
False
Different scientists may get different solutions to the same problem.
Understanding Experimental Design
A process of discovery…
The Controversy Over Spontaneous Generation
Problem: What causes tiny living things to appear in decaying broth?
Spallazani’s Hypothesis: Microbes come from the air. Boiling will kill them.Needham’s Hypothesis: Spontaneous generation-Life forms arose from non-living matter.
1700’s
John Needham
Lazzaro Spallanzani
NeedhamOpen flask >
SpallazaniClosed flask >
Experimental Designs with
flaws
Louis Pastuer …disproved the idea of spontaneous generation of life.
1800’s
Louis Pasteur ended the debate with his famous swan-neck flask experiment, which allowed air to contact the broth. Microbes present in the dust were not able to navigate the winding bends in the neck of the flask.
Controlled all of the variables in the experiment--- GOOD EXPERIMENTAL DESIGN
Objectivity is the key to good science.
To be objective, experiments must be designed and conducted in a way that does not introduce
bias into the study.
Soooo…what is good science?
The Beginnings of Immunologyusing the scientific method
Edward Jenner and the first vaccine:
COWPOX : Infectious disease that caused mild discomfort, aching, a few pustules, some swelling…symptoms that disappeared in a few days. No biggie.
SMALLPOX: Infectious disease that caused massive disfigurement, sometimes blindness, and often death.
Dr. Jenner was aware of farm workers' belief that if you had cowpox in the past, you wouldn’t get smallpox.
The Beginnings of ImmunologyEdward Jenner and the first vaccine.
Question: Does having cowpox make a person immune to smallpox?
Hypothesis: If someone is infected with cowpox, then they will be immune to smallpox because having cowpox keeps a person from getting smallpox.
Experiment: Jenner made small incisions or punctures in arms of human subjects and rubbed in cowpox material (pus) in order to infect them with cowpox.
Analysis & Conclusion: He saw that people that he infected with cow pox, when later exposed to smallpox, would get a little bit sick, but never come down with a full-blown case of smallpox. Cowpox infection prevents smallpox infection.
Present Results / Peer Evaluation: At first his peers doubted the safety and value of his treatment, but eventually the importance of the cowpox inoculum was recognized.
1800’s – English physician
Vaccination was not without its critics. In this cartoon from 1802, the British satirist James Gillray implied that vaccination caused people
to become part cow.
Fun Fact
SCIENTIFIC METHOD
The series of steps that scientists use to answer questions and solve problems is often called the scientific method. The scientific method is not a rigid procedure. Scientists may use all of the steps or just some of the steps of the scientific method. They may even repeat some of the steps. The goal of the scientific method is to come up with reliable answers and solutions.
Scientific Method (Inquiry)Observation, Question or
Problem
Hypothesis
Experiment/TestData/Analysis
Conclusion
Publish
Observation Question • The scientific
method starts with a question about something that is observed:
• How, What, When, Who, Which, Why, or Where?
Hypothesis• A statement of an answer to a question or problem. • A good hypothesis is testable explanation. • If an experiment cannot be designed to test the
hypothesis, it is untestable, and the investigation can go no further.
If _ [I do this]__ then _[this]__ will happen___because_[why]__.
Experiment/TestPerhaps the most familiar way isto conduct a controlled experiment.A controlled experiment tests onlyone factor at a time. A controlledexperiment has a control group andone or more experimental groups.All the factors for the control andexperimental groups are the sameexcept for one factor, which iscalled the independent variable. Bychanging only one factor, you cansee the results or dependent variableof the changed variable .
Data-AnalysisAfter completing an experiment observations,and collected data are evaluated.
Tables and graphs areoften used in this step toorganize the data.
ConclusionBased on the analysisof the data concludewhether or not theresults support thehypothesis.• Check for errors.• Investigate again• Make a new hypothesis
Publish• Results are verified
by independent duplication and publication in a peer-reviewed journal
• Independent duplication = Two or more scientists from different institutions investigate the same question separately and get similar results.
• Peer-reviewed journal. = A journal that publishes articles only after they have been checked for quality by several expert, objective scientists from different institutions.
Scientific Theory vs. Law
Scientific Theory vs. LawTHEORYExplanation for an observation or
phenomena that is confirmed by a large amount of evidence or tests (experiments).
Example:
Germ theory of disease - Infectious diseases result from the action of microorganisms.
LAWA statement of a scientific principle
that appears to be without exception at the time it is made, and always works the same way under the
same conditions; A scientific rule. Example:
Newton's First Law of Motion (Law of Inertia) - every object either remains at rest or in continuous motion with constant speed unless acted upon by an outside force.
Treponema pallidum - ♪ (Trep-o-neemah pal-lid-um)
So, what's the difference?
A SCIENTIFIC THEORY
- are typically non-mathematical.
A SCIENTIFIC LAW
- are often mathematically defined
• Looking at things this way helps to explain, in part, why physics and chemistry have lots of "laws" whereas biology has few laws (and more theories).
• In biology, it is very difficult to describe all the complexities of life with "simple" (relatively speaking!) mathematical terms.