Presentation on theme: "Pretest What is science?"— Presentation transcript:
1 Pretest What is science? What is the difference between a hypothesis, a theory, and a law?What are the steps of the scientific method?What is a control group, an independent variable, and a dependent variable?
9 The Scientific Method The Problem The Procedure The Data The ConclusionAsk a QuestionForm a TESTABLE hypothesisTest the hypothesis with an experimentCollect dataAssemble into chartsAccept or reject hypothesis
10 Example of the Scientific Method Suppose you want to see if playing music makes a bean plant grow taller.What would your hypothesis be?Design an experiment to test your hypothesis. Say that you have 50 seedlings to start with.
11 Playing Music Makes Bean Plants Grow Taller Play music for all 50 seedlings.Measure: How high do the plants grow?Results: The plants grew an average of 10 inches.What is the problem with this experiment?
12 Playing Music Makes Bean Plants Grow Taller Group 1: No music CONTROL GROUPGroup 2: MusicMeasure: How high do the plants grow?
13 Variables Group 1: No music CONTROL GROUP Group 2: Music for 1 hour a dayGroup 3: Music for 2 hours a dayHow would you plot your results?What TWO things are changing?
14 What are the two variables? How much music was played?How tall did the plants grow?
15 Variables How much music was played? Independent variable (manipulated)How tall did the plants grow?Dependent variable (responding)The dependent variable DEPENDS on the independent variable.How tall the plants are DEPENDS on how much music is played.
16 What is wrong with this experiment? You decide to see if taking vitamin “Q” will make your pet rats go through a maze faster. You feed one group of rats vitamin “Q” and give them extra food and water. You give the rest of your rats no vitamin, and only normal amounts of food and water.
17 CARDINAL RULE!!!!!!!!!!!!!!!!!!Only test ONE variable at a time!!!!!!!
18 What is wrong with this experiment? You have two rats. You give one vitamin “Q” and the other gets no vitamin.
20 Observations and Inferences You go the movies one afternoon. When you come out of the theater, you notice that the sidewalk is wet. “It must have rained,” you think to your self.What did you OBSERVE?What did you INFER?
21 Observation: the sidewalk is wet Information gathered using one or more of your sensesInference: it rainedYour INTERPRETATION of what you observed