2 What is Science Science What is science? begins with curiosity and often ends with discoveryis a system of knowledge and the methods you use to find that knowledgeAsk : what is science?
3 Demo – Candle in a JarCan 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 dioxideThe candle will go out once the oxygen in the jar is used up. (lid or aluminum foil)
4 Steps in the Scientific Method ObservationHypothesisExperimentData CollectionConclusionRetestCan 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?
5 Observations Gathered through your senses A scientist notices something in their natural world
6 ObservationsAn example of an observation might be noticing that many salamanders near a pond have curved, not straight, tailsIs information that you obtain through your sensesIs an observation required in order for you to arrive at a question?
7 Hypothesis A suggested solution to the problem. Must be testable Sometimes written as If…Then… statementsPredicts an outcomeWhat 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?
8 HypothesisAn example of a hypothesis might be that the salamanders have curved tails due to a pollutant in the moist soil where they live.
9 A procedure to test the hypothesis. ExperimentA procedure to test the hypothesis.
10 Variable – factor in the experiment that is being tested
11 A good or “valid” experiment will only have ONE variable!
12 Scientific Experiments Follow Rules An experimenter changes one factor and observes or measures what happens.
13 The Control VariableThe experimenter makes a special effort to keep other factors constant so that they will not effect the outcome.Those factors are called control variables.
14 What is the Purpose of a Control? Controls are NOT being testedControls are used for COMPARISON
15 Other VariablesThe factor that is changed is known as the independent variable.The factor that is measured or observed is called the dependent variable.
16 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.
17 What are the Variables in Your Experiment? Varying the route is the independent variableThe time it takes is the dependent variableKeeping the same walker throughout makes the walker a control variable.
18 One more thing… it is best to make several trials with each independent variable. An experiment must be repeatable for it to be valid!
19 Remember: To be a Valid Experiment: Two groups are required --- the control & experimental groupsThere should be only one variable
20 Data Results of the experiment May be quantitative (numbers) or qualitativeQuantitative is something you can count, qualitative is descriptive
21 DataMust be organizedCan be organized into charts, tables, or graphs
22 ConclusionThe answer to the hypothesis based on the data obtained from the experiment
23 In order to verify the results, experiments must be retested.
24 REMEMBER: Really Quiet Hippos Eat Dark Chocolate Solving a Problem1)Identify a Problem2) State Observations about the problem3) Form a Hypothesis about the problem (if…then…)4) Design an Experiment to test the hypothesis5) Collect Data6) Form a Conclusion7) RetestREMEMBER: Really Quiet Hippos Eat Dark ChocolateResearch; Question; Hypothesis; Experiment; Take Data; Form Conclusions
25 Scientific theory What is a theory? A well-tested explanation for a set of observations or experimental resultsNot the same as the way we use ‘theory’ in everyday languageAre NEVER proven, but become stronger (or weaker) with new informationEmpirical evidence (by observation or experiment)
26 Scientific Lawis a statement that summarizes a pattern observed in natureDescribes an observed pattern in nature without attempting to explain it (the explanation is given through a theory)