Science and the Scientific Method

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Science and the Scientific Method
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Goal of Science

• To investigate and understand nature
• To explain events in nature
• To use those explanations to make useful
  predictions

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Characteristics of living things

• Living things are made up of units called cells
• 2. Living things reproduce
• 3. Living things have a genetic code (DNA or RNA)
• 4. Living things grow and develop

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Characteristics of living things cont.

• 5. Living things obtain and use materials and
  energy
• 6. Living things respond to their environment
• 7. Living things maintain a stable environment-
  homeostasis
• 8. Taken as a group, living things change over
  time

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Growth and Development

• Children Grow- get bigger
• Develop- change body form

• Growth without development

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Figure 1-8 Redis Experiment on Spontaneous
Generation
Section 1-2
OBSERVATIONS Flies land on meat that is left
uncovered. Later, maggots appear on the meat.
HYPOTHESIS Flies produce maggots.
PROCEDURE
Uncovered jars
Covered jars
Controlled Variables jars, type of
meat, location, temperature, time
Several days pass
Manipulated Variables gauze covering that keeps
flies away from meat
Responding Variable whether maggots appear
Maggots appear
No maggots appear
CONCLUSION Maggots form only when flies come in
contact with meat. Spontaneous generation of
maggots did not occur.
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Scientific Theory

• Science Theory means that a belief based on
  observation has been tested and stood the test of
  time (has never been disproved).
• New discoveries in science occasionally change a
  theory.

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Observation

• Observation involves using one or more of the
  senses- (sight, hearing, touch, smell, and
  taste)- to gather information.
• Observations can be quantitative or qualitative
• quantitative- involving numbers
• qualitative- characteristics that cannot be
  easily measured or counted
• Data- the information gathered through
  observation (also called evidence)

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Are these qualitative or quantitative?

• Its red
• Its hot
• Its 200 miles away
• Its smaller than one cm
• It burns

Qualitative
Qualitative
Quantitative
Quantitative
Qualitative
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Observation Vs. Inference
Observation- gathered info using your
senses. Inference- logical interpretation based
on prior knowledge and experience

• Dependant Independent Variable Worksheet

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Explaining the evidence

• Hypothesis- a statement that is a possible
  explanation for a set of observations or answers
  to a scientific question
• A hypothesis must be testable. (not useful if it
  cant be tested)
• Ex. When a student studies more he/she gets
  better grades.

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Scientific Method
Used to Design an Experiment
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State the Problem
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Analyze Results
2
Form a Hypothesis
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Draw a Conclusion
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Set Up a Controlled Experiment
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Publish Results
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Record Results- (collect data)
Many times you see steps combined (not always 7
steps but always same procedure)
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Variables and a controlled experiment

• Controlled experiment- an experiment where only
  one variable is changed.
• Variable is something that changes in an
  experiment
• When you change one variable another variable
  changes
• Ex. When you add more light to a plant
  experiment there is more oxygen produced

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Variables

• Two Types of Variables
• Independent variable- factor in an experiment
  that a scientist purposely changes (also called a
  manipulated variable)
• Dependant variable - factor in an experiment that
  may change due to a independent variable (also
  responding variable)

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Ex. When you add more light to a plant experiment
there is more oxygen produced
Independent variable- more light
Dependant variable- more oxygen produced
When Graphing plot the independent variable on
the x axis
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Drawing Conclusions
1. Production of a model or graph helps show
relationships among data
a. It is essentially the explanation supported
by the data
i. can be visual, verbal, or mathematical
ii. can be used to generate new hypothesis or
predictions
2. Inferences are drawn from data gathered a
conclusion based on facts/premises
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3. After many related hypothesis have been
tested and supported w/ experimental evidence,
a theory may be formed
a. Supported by considerable evidence
believe to be true