what do scientists do?
Post on 24-Feb-2016
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What do scientists do?
Science Jobs
MicrobiologistChemistPhysicistAstronomerMeteorologistZoologistGeologistOceanographerAnthropologist
How does science work?
The Scientific Method
Scientific Tools
1. computer technology2. internet3. libraries4. scientific method and experiments5. models6. statistics7. pictures/maps/graphs
Hypothesis
a statement that uses a few observations
an idea based on observations without experimental evidence
Theoryuses many observations and has
loads of experimental evidence
can be applied to unrelated facts and new relationships
flexible enough to be modified if new evidence introduced
Lawstands the test of time, often without change
experimentally confirmed over and over
can create true predictions for different situations
has uniformity and is universal
Scientists use experiments to search for cause and effect relationships in nature.
What is a controlled experiment?
controlled experimentKeep everything the same except for
the single variable being tested.
Variables
A variable is something that can be changed in the experiment. It is what you are testing.
Everything else must be the same and only one variable or condition is altered or changed.
Control Group
A control group receives the same attention as the test groups, however, it will not be influenced by the variable the other groups are testing.
example• QUESTION: How will the amount of
fertilizer used affect plant growth?
• HYPOTHESIS: Increased dosages of fertilized will cause greater growth in tomato plants.
• TEST VARIABLE: The amount of fertilizer used.
Does fertilizer make a plant grow bigger?
• Amount of fertilizer measured in grams.
• Growth of the plant measured by its height• • Growth of the plant measured by the number
of leaves
Controls• Same size pot for each plant
• Same type of plant in each pot
• Same type and amount of soil in each pot
• Same amount of water and light
• Make measurements of growth for each plant at the same time
"The many variables above can each change how fast a plant grows, so to insure a fair test of the fertilizer, each of them must be kept the same for every pot."
http://videos.howstuffworks.com/hsw/5886-scientific-method-controlled-experiment-video.htm
Variables
independent variable
dependent variable
Independent Variable
• The independent variable is the one that is changed by the scientist.
• A good experiment has only one independent variable.
• The scientist changes the independent variable and observes what happens.
Dependent Variable
• The scientist focuses observations on the dependent variable to see how it responds to the change made to the independent variable.
Units of Measure
REVIEW
I. scientific methodII. hypothesisIII. theoryIV. natural lawV. controlled experimentVI. variablesVII. units of measure
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