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Science as a ProcessScience as a Process

Chapter 1 Section 2Chapter 1 Section 2

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ObjectivesObjectives ExplainExplain how science is different from other forms of human how science is different from other forms of human

endeavor.endeavor. IdentifyIdentify the steps that make up scientific methods. the steps that make up scientific methods. AnalyzeAnalyze how scientific thought changes as new information is how scientific thought changes as new information is

collected.collected. ExplainExplain how science affects society. how science affects society.

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Goal of ScienceGoal of Science To explain natural phenomena To explain natural phenomena

by asking questions about by asking questions about natural events and answer natural events and answer them through experimentation them through experimentation and examination.and examination.

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Behavior of Natural SystemsBehavior of Natural Systems Scientists assume that:Scientists assume that:

Nature is understandable.Nature is understandable.

Similar forces in similar situations Similar forces in similar situations cause similar results (even if the cause similar results (even if the forces involved are complex).forces involved are complex).

Nature is predictable.Nature is predictable.

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Natural Systems are ComplexNatural Systems are Complex

So a high level of predictability can So a high level of predictability can be difficult to achieve. To increase be difficult to achieve. To increase our understanding, we follow the our understanding, we follow the same basic steps in an same basic steps in an investigation.investigation.

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Science Is A MethodScience Is A Method An organized and logical approach An organized and logical approach

to scientific research. The following to scientific research. The following are guidelines to problem solving.are guidelines to problem solving.

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Steps In The Scientific MethodSteps In The Scientific Method Additions to the flowchart at right:Additions to the flowchart at right: 1. Before a problem can be 1. Before a problem can be

identified, an identified, an observationobservation must be must be made.made.

2. If experiments and observations 2. If experiments and observations do not support the hypothesis, do not support the hypothesis, then the hypothesis must be then the hypothesis must be rejected.rejected.

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To Ask A QuestionTo Ask A Question

We often begin with We often begin with observationsobservations, , using the senses to gather using the senses to gather information about the world. information about the world. These lead to questions.These lead to questions.

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Form A HypothesisForm A Hypothesis This is a possible explanation This is a possible explanation

or solution to a problem based or solution to a problem based on close and careful on close and careful observation or on known facts observation or on known facts about similar events.about similar events.

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Test The HypothesisTest The Hypothesis Usually done by performing an Usually done by performing an

experimentexperiment, a procedure that , a procedure that is carried out according to is carried out according to certain guidelines.certain guidelines.

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Control GroupControl Group

A control has the same conditions A control has the same conditions as the experiment except for the as the experiment except for the variable being tested. An variable being tested. An experiment that contains a control experiment that contains a control is a is a controlled experiment.controlled experiment.

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Draw ConclusionsDraw Conclusions If the hypothesis fits the known If the hypothesis fits the known

facts, it may be accepted as true.facts, it may be accepted as true. If the results differ from what was If the results differ from what was

expected, the hypothesis may be expected, the hypothesis may be changed or discarded.changed or discarded.

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This Leads ToThis Leads To New questions, further study, new New questions, further study, new

knowledge, and new methods of knowledge, and new methods of inquiry.inquiry.

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Scientific Measurements and AnalysisScientific Measurements and Analysis

Measurement is an important method of Measurement is an important method of gathering information and is the gathering information and is the comparison of an object or event with a comparison of an object or event with a standard unit.standard unit.

Scientific standards of measurement Scientific standards of measurement follow the follow the International System of Units, International System of Units, or SI (see p.or SI (see p.

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Accuracy and PrecisionAccuracy and Precision AccuracyAccuracy – How close a measurement is to the true – How close a measurement is to the true

value of the thing being measured.value of the thing being measured. PrecisionPrecision – The exactness of the measurement. – The exactness of the measurement.

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Accurate or Precise?Accurate or Precise?

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Purpose or Question“problem"

Hypothesis

Controlled Variable(s)(constant across treatments

Responding Variable(measurement)

manipulated Variable

Procedure“methods”

Prediction

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TreatmentsTreatments

Appropriate levels (values) that you Appropriate levels (values) that you assign to the independent variable.assign to the independent variable.

Examples?Examples?

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Controlled Variable(s)Controlled Variable(s)

All independent variables other All independent variables other than the one being studied that than the one being studied that are to be held constant.are to be held constant.

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Do we run the experimentDo we run the experiment

nownow??

NO!NO!

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A A predictionprediction needs to be needs to be made made beforebefore you run the you run the

experiment.experiment. What is a prediction?What is a prediction? A prediction is the expected result of A prediction is the expected result of

an experiment (your “educated an experiment (your “educated guess”). Usually it takes the form of guess”). Usually it takes the form of an “if an “if then” statement. then” statement.

Your prediction has to be based on Your prediction has to be based on your hypothesis.your hypothesis.

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Collect dataCollect data..

What is data?What is data?It is the actual results of It is the actual results of

your experiment. your experiment. (not the character (not the character

on Star Trek)on Star Trek)

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Form a Form a conclusionconclusion..What is a conclusion?What is a conclusion? A conclusion is a statement on A conclusion is a statement on

whether your hypothesis is whether your hypothesis is supported or not. supported or not.

If your data = your prediction, then If your data = your prediction, then your hypothesis is supported.your hypothesis is supported.

If your data = your prediction, then If your data = your prediction, then your hypothesisyour hypothesis is is notnot supported. supported.

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Observations and ModelsObservations and Models You can’t experiment on You can’t experiment on

everything, so we often make everything, so we often make further observations and then test further observations and then test the hypothesis by comparing it to the hypothesis by comparing it to the evidence.the evidence.

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ModelsModels

A description, representation, or A description, representation, or imitation of an object, system, imitation of an object, system, process, or concept.process, or concept.

Many kinds (physical, graphical, Many kinds (physical, graphical, conceptual, mathematical, conceptual, mathematical, computer, etc.).computer, etc.).

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Acceptance of Scientific IdeasAcceptance of Scientific Ideas

Conclusions are introduced to Conclusions are introduced to the scientific community and the scientific community and undergo review and testing undergo review and testing before the ideas are accepted.before the ideas are accepted.

Voltaire

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Publication of Results and ConclusionsPublication of Results and Conclusions

Results are commonly presented in Results are commonly presented in scientific journals (written in a standard scientific journals (written in a standard format) or at professional meetings.format) or at professional meetings.

Galileo Galilei1564-1642

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Peer ReviewPeer Review

The process in which several experts on a The process in which several experts on a topic review another expert’s work before topic review another expert’s work before the work gets published. This reduces the work gets published. This reduces experimental bias and ensures that valid experimental bias and ensures that valid results are published.results are published.

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Scientific TheoryScientific Theory

After an idea has been tested and After an idea has been tested and reaches general acceptance, it reaches general acceptance, it may help form a may help form a theorytheory, an , an explanation that is consistent with explanation that is consistent with all existing tests and observations.all existing tests and observations.

Charles Darwin

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LawsLaws

Theories (explanations) are Theories (explanations) are often based on scientific laws often based on scientific laws (which describe) are general (which describe) are general statements that explain how statements that explain how the natural world behaves the natural world behaves under certain conditions and under certain conditions and for which no exceptions have for which no exceptions have been found.been found.

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Theories are NOT guesses!Theories are NOT guesses!

They can be changed if They can be changed if conflicting information is conflicting information is discovered in the future.discovered in the future.

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Importance of Interdisciplinary ScienceImportance of Interdisciplinary Science

The exchange of ideas between The exchange of ideas between different fields of science allows us different fields of science allows us to identify explanations tat fit a to identify explanations tat fit a wide range of evidence, and the wide range of evidence, and the explanation is more likely to be explanation is more likely to be accurate.accurate.

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Science and SocietyScience and Society

Advances in science can have Advances in science can have important and lasting effects. It is important and lasting effects. It is also used to develop new also used to develop new technologies, which may solve technologies, which may solve problems or create new ones.problems or create new ones.

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AssignmentsAssignments Section 1.2 Outline/NotesSection 1.2 Outline/Notes Key termsKey terms Direct Reading WorksheetDirect Reading Worksheet WednesdayWednesday –Accuracy Lab –Accuracy Lab FridayFriday – Show N Tell EC – Show N Tell EC