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.