2 Science A way of learning about the natural world Includes all of the knowledge gained by exploring the natural worldThis knowledge is always growing and changing as scientists ask new questions and explore new ideas
3 Scientific InquiryScientific: Of or relating to the practice of scienceInquiry: A close examination of a matter in a search for information or truthScientific Inquiry: The ways in which scientists explore the natural world
4 How Does Scientific Inquiry Work? Scientific Method:Make observations and/or inferencesAsk questionsDevelop hypothesesDesign experimentsMake measurementsCollect dataInterpret dataDraw conclusionsCommunicate
5 Make Observations and Inferences Observation: Using one or more of your senses to collect dataInference: An interpretation of an observation that is based on evidence or prior knowledgeData: Facts, figures and other evidence gathered through observation
6 Question You ask a question about what you observe. State the problem or question.Example: Does the drop height affect the bounce height of a superball?
7 Developing a Hypothesis Hypothesis: A possible explanation for a set of observations or answer to a scientific questionA hypothesis must be something that can be testedWorded as an If Then statementHypotheses can either be supported or disprovedExample: If a superball is dropped from increasing heights then the bounce heights will also increase because…
8 Null HypothesisA hypothesis that can be rejected-it essentially states that the variables will have no effect on the outcome of the experimentWhy use a Null Hypothesis?You can never have enough support for a hypothesis to say that it is the sole explanation of a phenomenon, but you can have enough data to show that it is not the sole explanation of a phenomenon.
9 Designing an experiment to test a hypothesis After you state your hypothesis, you must design an experiment to test it.You figure out a way to test whether the hypothesis is supported.Control group– nothing changedExperimental group – one variable changedThe outcome must be measurable (quantifiable).Record and analyze data.
10 Designing a Controlled Experiment. An experiment in which all of the variables except for one are remain the sameAn experiment that is designed to compare an experimental group with a control group.Ideally, a control group and an experimental group differ in only one variable.Control group serves as a comparison to measure against
11 Experiment VariablesVariable: Factors that can change in an experimentManipulated (Independent) Variable: The variable that is changed during the experimentResponding (Dependent) Variable: The factor that changes because of the manipulated variableVariable that is measured in the experiment
12 Variables Independent variable Dependent variable Example: Does the drop height affect the bounce height of a superball?We know the drop heights we will use.Dependent variableWe don’t know the bounce height before we start. It is what is being measured.
13 ConstantsConstant: a variable that does not change for the duration of an experiment; a value that remains the sameExamples: Does the drop height affect the bounce height of a superball?The superball does not change during the experiment. The same force is applied during each trial.
14 Interpreting DataYou do the experiment using the method you came up with and record the results.After the data are collected, they must be organized and interpretedCreate data tables, graphs to represent dataPerform calculations that will determine what results mean (averages, percentages, totals)Identify possible sources of errors
15 Drawing ConclusionsAfter you have organized and interpreted your data, you must draw a conclusion.You need to decide if the data support your original hypothesis.
16 RetestIn order to verify the results, experiments must be retested.
17 CommunicatingScientists must communicate their findings to other scientists.This contributes to the growth of the body ofscientific knowledge.
18 ← a tentative answer to some question. Figure 1.18
20 Scientific TheoriesScientific Theory: A well-tested concept that explains a wide range of observations.A theory is based on thousands of experiments done by different scientists.A theory is much broader in scope than a hypothesis.Theories only become widely accepted in science if they are supported by an accumulation of extensive and varied evidence.Future testing may prove a theory to be incorrect.