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What is Science?. Science is an organized way of attempting to understand the natural world, structurally and operationally. We are always: - looking for ways to improve our quality of life - trying to understand how systems work - attempting to improve on an existing system
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What is Science? Science is an organized way of attempting to understand the natural world, structurally and operationally. We are always: - looking for ways to improve our quality of life - trying to understand how systems work - attempting to improve on an existing system - atlatl, pump toothpaste
The Need for Proof • Evidence is based on observations. • Information gathered using the senses during an observation is called data (sing. datum).
Data • Data can be qualitative or quantitative. • Qualitative – no specific number, rather a comparison or estimate • ex. big, blue, some, herd, bunch • Quantitative – specific number given in an attempt at exacting detail • ex. 21.6m, 662miles, 13, 17 reindeer
Give me some of your freedom fries. • Qualitative • Quantitative
Get a dozen eggs. • Qualitative • Quantitative
Only a few dollars. • Qualitative • Quantitative
There are nine geese on the field. • Qualitative • Quantitative
Go get some firewood. • Qualitative • Quantitative
An estimation or prediction based on previous experiences or observations are called inferences • You can infer about whether or not a fish with large, sharp teeth eats other fish because of your previous experiences or observations of fish with large, sharp teeth.
Hypothesis • “Educated guess” • Testable prediction • Possible explanation of an experience or observation in nature Always as a statement, never as a question There may or may not be an underlying knowledge about the hypothesis
Theory • Best possiblescientific explanation of an experience or observation in nature. • Have not been tested • Can not be tested There is an underlying knowledge about a theory, both observationally and experimentally
Scientific Law • Always true • Can not be circumvented or broken
Birds may have descended from dinosaurs. • Hypothesis • Theory • Law
Energy can be transformed from one form to another. • Hypothesis • Theory • Law
Dogs will eat all kinds of cheese. • Hypothesis • Theory • Law
Gravity affects all objects in the universe. • Hypothesis • Theory • Law
Tide brand laundry detergent gets your clothes cleaner. • Hypothesis • Theory • Law
RIGHT or WRONG?GOOD or EVIL? Ethics and Values in Science • Ethics refer to whether or not an action or plan is considered right or wrong by a group or society. • Your values, which differ from person to person, help you decide whether or not something is ethical. Ex. charging for cures, man v. environment
The Scientific Method An organized procedure to determine whether or not a statement (or idea) is valid. Every scientist follows the scientific method, but not every scientist uses all of the scientific method.
The Scientific Method • Determine the Problem • Ask a question that you would like answered about a particular topic • Gather data • Research your topic using observations or other sources of data (books, magazines) • Make a hypothesis • Make a statement concerning your topic • Must be testable • can not be a question
The Scientific Method • Experiment • Test your hypothesis in a controlled experiment setting • Analyze Results • Use the data from your experiment to support your hypothesis • Conclusion • A restatement of the hypothesis that takes the results of the experiment into account • The data may not support the hypothesis
Which step of the Scientific Method is a testable statement? • Determine the Problem • Analyze Results • Experiment • Hypothesis
Which step of the Scientific Method proves or disproves the Hypothesis? • Gather Data • Analyze Results • Experiment • Conclusion
Which step of the Scientific Method has us research the work done on our question by others? • Determine the Problem • Gather Data • Experiment • Conclusion
Which step of the Scientific Method is a restatement of the Hypothesis? • Gather Data • Analyze Results • Experiment • Conclusion
Which step of the Scientific Method has us make graphs and charts to determine the outcome of our Experiments? • Gather Data • Analyze Results • Experiment • Conclusion
Controlled Experiments Have at least two groups: Control Group Used to see what happens when nothing is changed As many variables are kept the same as possible Experimental Group Only one variable is changed Can be more than one group, changing the same variable
Variables • Control variable • Kept the same from group to group, trial to trial
THE CAUSE • Experimental Variable • Also called the Manipulated variable, the Independent variable • Condition changed from the control group to elicit a response
THE EFFECT • Dependant Variable • The outcome of the changed variable • What changed because of what you changed for the experimental group
Reproducible Results • To be considered valid, a successful experiment must be replicable (repeatable). • Scientists often publish their lab reports in journals so that other scientists can try these experiments. • Make certain that the hypothesis you declare is based on a clear cause-and-effect relationship.
What may have gone wrong? • If the Results and Conclusions do not support your hypothesis, check your procedures for any sources of error. • Sources of error can be included in laboratory report to help other scientists determine what may have gone wrong in your experiment.
Which variable do you make certain does not change for the experiment? • Control Variable • Experimental Variable
Anything that may have affected your data in an experiment should be described under which part of a lab report? • Premise • Procedures • Sources of Error • Conclusion
Any data which does not seem to follow the other data in an experiment could be caused by • Faulty equipment • Human error • Flawed chemicals/subjects • All of the above
Which variable do you change for the experiment? • Control Variable • Experimental Variable
A sample Scientific Investigation • To prove or disprove the hypothesis, run an experiment • Make sure that the experimental (independent) variable is the only one that changes
A sample Scientific Investigation • Define the question • Does smoking cause cancer? • Gather Data • Ask doctors, hospitals, people in cancer wards • Make a hypothesis • Smoking causes cancer • HERE COME THE LAWSUITS!
Analysis of Results • Hypothesis disproved • If smoking causes cancer, all subjects should have gotten cancer • Some of the control group developed cancer for no apparent reason
Conclusion • Smoking does not cause cancer • Surgeon General’s warning • Because of the high correlation, you can restate your hypothesis with strong conditional wording • Smoking greatly increases the risk of cancer, emphysema, pregnancy complications, etc.