# Scientific Method Right ppt.

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Scientific Method Right ppt

What is Science Science What is science?
begins with curiosity and often ends with discovery is a system of knowledge and the methods you use to find that knowledge Ask : what is science?

Demo – Candle in a Jar Can you prove the existence of something invisible? What do you predict will happen if the jar is covered? What invisible substances did you assume in your explanation? Oxygen, carbon dioxide The candle will go out once the oxygen in the jar is used up. (lid or aluminum foil)

Steps in the Scientific Method
Observation Hypothesis Experiment Data Collection Conclusion Retest Can you think of something where you have to do things in a specific order? (ie playing a game) What about something where the order is flexible? (ie cleaning a room). Do you think order is important in science?

A scientist notices something in their natural world

Observations An example of an observation might be noticing that many salamanders near a pond have curved, not straight, tails Is information that you obtain through your senses Is an observation required in order for you to arrive at a question?

Hypothesis A suggested solution to the problem. Must be testable
Sometimes written as If…Then… statements Predicts an outcome What does it mean to be testable? Why would we want it to be testable? Make a hypothesis about why a salamanders tail might curved near a pond. be What can you do with a your 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.

A procedure to test the hypothesis.
Experiment A procedure to test the hypothesis.

Variable – factor in the experiment that is being tested

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

An experimenter changes one factor and observes or measures what happens.

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?
Controls are NOT being tested Controls are used for COMPARISON

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
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?
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.

One more thing… it is best to make several trials with each independent variable.
An experiment must be repeatable for it to be valid!

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

Data Results of the experiment
May be quantitative (numbers) or qualitative Quantitative is something you can count, qualitative is descriptive

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

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

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

REMEMBER: Really Quiet Hippos Eat Dark Chocolate
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 REMEMBER: Really Quiet Hippos Eat Dark Chocolate Research; Question; Hypothesis; Experiment; Take Data; Form Conclusions

Scientific theory What is a theory?
A well-tested explanation for a set of observations or experimental results Not the same as the way we use ‘theory’ in everyday language Are NEVER proven, but become stronger (or weaker) with new information Empirical evidence (by observation or experiment)

Scientific Law is a statement that summarizes a pattern observed in nature Describes an observed pattern in nature without attempting to explain it (the explanation is given through a theory)