Fact or Fiction? • Turtle eggs develop into males in cold temperatures and females in warmer temperatures • Insect-eating bats can eat as many as 3000 insects in one night • Pill-bugs have blue blood, do not urinate, and eat their own poop • Average garden snails have up to 14,175 teeth located on their tongue • The average American teenager eats about 825 kilograms (1818.81 lbs) of food each year
Believe it or not, all of those statements are FACTS! • To gather knowledge about the natural world, scientists OBSERVE what happens around them • They then come up with ideas to EXPLAIN what they observed • Then, they perform EXPERIMENTS to test their explanations • This is “good science”!
Tell Me More! • Science is a “process” (a VERB!) • Think about this question: “I have high cholesterol, what should I do?” • Take cholesterol lowering medication. • Consult your astrologer. • Pray to the god Baal and sacrifice a goat on Mount Fuji.
The Scientific Method • A series of steps which are followed in order to logically solve a problem. • YOU follow the Scientific Method ALL THE TIME!
Steps in the Scientific Method • Observation • Problem • Hypothesis • Experiment • Data • Data Collection • Data Analysis • Conclusion • Repeat
YOU Follow the Steps of the Scientific Method EVERY DAY! • You make Observations • See a Problem to Solve • Make a Hypothesis • Experiment • Collect Data and Analyze the Results • You make a Conclusion • Repeat or Retry if necessary
How are YOU going to Remember the Steps in the Scientific Method??? • Observe • Problem • Hypothesis • Experiment • Data • Data Collection • Data Analysis • Conclusion • Repeat • Oh! • Please • Have • Extra • Delicious • Candy • Ready
Observe • Observations are gathered through your senses • A scientist (and you!) notices (observes) something in the natural world
Problem • What is the Problem you are trying to solve?
Hypothesis • A suggested solution for (reason for) the problem or observation • An Educated Guess • Must be testable • Predicts an outcome
Experiment • An Experiment is a procedure set up to test the hypothesis
Valid Experiments • Any “factor” (thing that can influence) which is able to be changed in an experiment is called a Variable • Make sure only ONE variable is changed in an experiment!!!
Valid Experiments • A good (valid) science experiment tests a single variable that can be measured against a control. • A Control is the same experiment, leaving out the variable. • It is unchanged and used for comparison
Controlled Experiments • Controlled experiments are experiments where all factorsare the same between two test subjects, except for the single variable you changed
Control Groups • Control Group receives the same attention as the test groups, however, it will not receive the “treatment” (variable) as the other groups and is used for comparison
Independent Variable • The independent variable is sometimes called the manipulated variable • It is the one factor that is changed (manipulated) in the experiment
Dependent Variable • The dependent variable depends on what is being changed in the experiment • It is the outcome (result) that is measured
Scientific Experiments Follow Rules • A valid experiment changes only one factor andobserves or measureswhat happens • This is the data that is collected and analyzed!
What is the Purpose of a Control? • Controls are NOT being tested • Controls are used for COMPARISON • Controls sometimes use PLACEBOs
What is a Placebo? • PLACEBOs are fake “treatments” given to the control group to ensure that the control group doesn’t know what’s going on… • It is harmless and has no effect • A “sugar pill”
Data • Results of the experiment must be recorded and organized • Can be organized into charts, tables, or graphs
Conclusion • A Conclusion is the answer to the hypothesis based on the data obtained from the experiment • Does the data support or not support your hypothesis? • If it rejects it… Try Again!
Repeat/Retest In order to verify the results and make sure they are valid, an experiment must be reproducible - (able to be repeated / retested and get the same results)
One more thing… Valid experiments are repeated several times and get the same results, use a large sample group and are peer reviewed.
Theories vs. Laws • What does the word “Theory” mean? “A well tested / well supported / well accepted guess” (Webster’s Dictionary) • What is the difference between theory and law? “Evolution is a theory, it is not a law.” • When a theory has been tested many times and is accepted as fact, it becomes a Law.
So?????? • A successful, well tested hypothesis eventually becomes a Scientific Theory. • A successful, well tested, well supported, well accepted Theory becomes a Scientific Law.