Scientific Method

Scientific Method : Scientific Method

Steps in the Scientific Method : Steps in the Scientific Method Observation Hypothesis Experiment Data Collection Conclusion Retest

Graphic summary : Graphic summary

Observations : Observations Gathered through your senses A scientist notices something in their natural world

Observations : Observations An example of an observation might be noticing that many salamanders near a pond have curved, not straight, tails Or, say you go outside to go to work and you go to start your car. You turn the key to discover, it does not work.

Hypothesis : Hypothesis A suggested solution to the problem. Must be testable Sometimes written as If…Then… statements Predicts an outcome

Hypothesis : Hypothesis An example of a hypothesis might be that the salamanders have curved tails due to a pollutant in the moist soil where they live. OR: If the car does not start, it may be due to the battery not working.

Experiment : Experiment A procedure to test the hypothesis.

Experiment : Experiment Variable – factor in the experiment that is being tested

Experiment : Experiment A good or “valid” experiment will only have ONE variable!

Scientific Experiments Follow Rules : Scientific Experiments Follow Rules An experimenter changes one factor and observes or measures what happens.

The Control Variable : The Control Variable The experimenter makes a special effort to keep other factors constant so that they will not effect the outcome. Those factors are called control variables.

What is the Purpose of a Control? : What is the Purpose of a Control? Controls are NOT being tested Controls are used for COMPARISON

Other Variables : Other Variables The factor that is changed is known as the independent variable. The factor that is measured or observed is called the dependent variable.

Example of Controls & Variables : Example of Controls & Variables 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 Experiment? : What are the Variables in Your Experiment? Varying the route is the independent variable The time it takes is the dependent variable Keeping the same walker throughout makes the walker a control variable.

Slide 17 : Dependent vs. Independent Variables Independent Variable- what you choose to change intentionally Dependent Variable- depends/changes because of the Independent Variable. (what you measure and observe) YOU CAN ONLY CHANGE 1 VARIABLE AT A TIME IN AN EXPERIMENT!!!

One more thing… it is best to make several trials with each independent variable. : One more thing… it is best to make several trials with each independent variable.

Inquiry Wheel : Inquiry Wheel

Remember: To be a Valid Experiment: : Remember: To be a Valid Experiment: Two groups are required --- the control & experimental groups There should be only one variable

Data : Data Results of the experiment May be quantitative (numbers) or qualitative

Data : Data Must be organized Can be organized into charts, tables, or graphs

Conclusion : Conclusion The answer to the hypothesis based on the data obtained from the experiment

Retest : Retest In order to verify the results, experiments must be retested.

Review : Review Give a detailed explanation of how you will conduct the experiment to test your hypothesis. This is called a procedure. Be clear about the variables (elements of the experiment that change to test your hypothesis) versus your controls (elements of the experiment that do not change). Be very specific about how you will measure results to prove or disprove your hypothesis. You should include a regular timetable for measuring results or observing the projects (for example, every hour, every day, every week).

Template : Template Construct a Hypothesis: A hypothesis is an educated guess about how things work: "If _____[I do this] _____, then _____[this]_____ will happen.“ You must state your hypothesis in a way that you can easily measure, and of course, your hypothesis should be constructed in a way to help you answer your original question.

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Solving a Problem : Solving a Problem 1)Identify a Problem 2) State Observations about the problem 3) Form a Hypothesis about the problem (if…then…) 4) Design an Experiment to test the hypothesis 5) Collect Data 6) Form a Conclusion 7) Retest