scientific method. a. defining science pure science research that adds to the body of scientific...
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A. Defining Science
Pure Scienceresearch that adds to the body of scientific knowledge has no practical use
Applied Science (Technology)the practical application of scientific knowledge
A. Defining Science
PURE
human genetics
polymer science
atomic theory
study of the human ear
APPLIED
DNA fingerprinting
Lycra® spandex
nuclear weapons
hearing aids
A. Defining Science
Life Sciencethe study of living organisms
Earth Sciencethe study of Earth and space
Physical Sciencethe study of matter and energychemistry & physics
B. Problem-Solving
1. Identify the problem.What do you know?What do you need to know?
2. Plan a strategy.Look for patterns.Break the problem into smaller steps. Develop a model.
B. Problem-Solving
3. Execute your plan.
4. Evaluate your results.Did you solve the problem?Is your answer reasonable?
Identify - Plan - Execute - Evaluate
ObservationObservation
HypothesisHypothesis
ExperimentExperiment
Data Data CollectionCollection
ConclusionConclusion
RetestRetest
ObservationsObservations
Gathered through Gathered through your your sensessenses
A scientist notices A scientist notices something in their something in their
natural worldnatural world
ObservationsObservations
An An exampleexample of an of an observationobservation might be might be
noticing that many noticing that many salamanders near a salamanders near a
pond have curved, not pond have curved, not straight, tailsstraight, tails
HypothesisHypothesis
A suggested solution to A suggested solution to the problem.the problem.Must be Must be testabletestableSometimes written as Sometimes written as If…Then…If…Then… statements statementsPredictsPredicts an outcome an outcome
HypothesisHypothesis
An An example of a example of a hypothesishypothesis might be might be that the salamanders that the salamanders have curved tails due have curved tails due to a pollutant in the to a pollutant in the moist soil where they moist soil where they live. live.
ExperimentExperiment
VariableVariable – – factor in the factor in the experiment experiment that is being that is being
testedtested
ExperimentExperiment
A good or A good or “valid” “valid”
experiment experiment will only will only
have have ONE ONE variable!variable!
Scientific Experiments Follow Scientific Experiments Follow RulesRules
An experimenter changes one factor and observes or measures what happens.
The ControlThe Control
The experimenter makes a The experimenter makes a special effort to keep special effort to keep other other factors constantfactors constant so that so that they will not effect the they will not effect the outcome.outcome.
Those factors are called Those factors are called controls.controls.
What is the Purpose of a What is the Purpose of a Control?Control?
Controls are NOT being testedControls are used for COMPARISON
Other Variables
The factor that is changed is known as the independent variable. (manipulated Varable)
The factor that is measured or observed is called the dependent variable or Responding variable).
Example of Controls & Example of Controls & VariablesVariables
For example, suppose you want to figure out the fastest route to walk home from school. You will try several different routes and time how long it takes you to get home by each one. Since you are only interested in finding a route that is fastest for you, you will do the walking yourself.
What are the Variables in Your What are the Variables in Your Experiment?Experiment?
Varying the route is the Varying the route is the independent variableindependent variable The time it takes is the The time it takes is the dependent variabledependent variable Keeping the same walker Keeping the same walker throughout makes the throughout makes the walker a walker a control.control.
Remember: To be a Valid Remember: To be a Valid Experiment:Experiment:
Two groups are required --- the control & experimental groupsThere should be only one variable