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Science as a Process

Chapter 1 Section 2

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Objectives• Explain how science is different from other

forms of human endeavor.

• Identify the steps that make up scientific methods.

• Analyze how scientific thought changes as new information is collected.

• Explain how science affects society.

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Goal of Science• To explain natural

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

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Behavior of Natural Systems• Scientists assume that:

Nature is understandable.

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

Nature is predictable.

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Natural Systems are Complex• So a high level of

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

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Science Is A Method• An organized and logical

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

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Steps In The Scientific Method• Additions to the

flowchart at right:• 1. Before a problem

can be identified, an observation must be made.

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

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To Ask A Question• We often begin with

observations, using the senses to gather information about the world. These lead to questions.

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Form A Hypothesis• This is a possible

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

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Test The Hypothesis• Usually done by

performing an experiment, a procedure that is carried out according to certain guidelines.

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Variables

• Factors that can

be changed in an

experiment.

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Two Types of Variable• Independent: Factors

that can be changed by the person performing the experiment.

• Dependent: Variables that change as a result of a change in independent variables.

Usually only one independent variable is tested in an experiment.

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Control Group• A control has the same

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

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Draw Conclusions• If the hypothesis fits the

known facts, it may be accepted as true.

• If the results differ from what was expected, the hypothesis may be changed or discarded.

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This Leads To• New questions, further

study, new knowledge, and new methods of inquiry.

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Scientific Measurements and Analysis

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

• Scientific standards of measurement follow the International System of Units, or SI (see p. 870).

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Accuracy and Precision

• Accuracy – How close a measurement is to the true value of the thing being measured.

• Precision – The exactness of the measurement.

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Accurate or Precise?

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Observations and Models• You can’t experiment

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

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Models• A description,

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

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

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Acceptance of Scientific Ideas

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

Voltaire

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Publication of Results and Conclusions• Results are commonly

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

Galileo Galilei1564-1642

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Peer ReviewThe process in which several

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

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Scientific Theory• After an idea has been

tested and reaches general acceptance, it may help form a theory, an explanation that is consistent with all existing tests and observations.

Charles Darwin

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Laws• Theories are often

based on scientific laws, general statements that explain how the natural world behaves under certain conditions and for which no exceptions have been found.

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Theories are NOT guesses!

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

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Importance of Interdisciplinary Science

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

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Science and Society

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

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Conclusion• Science is different from other forms of

human endeavor in that the goal of science is to explain natural phenomena based on the ideas that nature is understandable and predictable.

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Conclusion• The steps of the scientific method are:

Observation

Asking a question

Forming a hypothesis

Further observations or testing

Organize and analyze data

Support or reject the hypothesis

Draw conclusions

Publish results

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Conclusion• Scientific thought can change as new

information is collected because this can lead to either the development of a theory or disproving or modifying an hypothesis.

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Conclusion• Science affects society because it is a part

of society and scientific advances influence society by introducing new ideas and technologies, for both good and ill.

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Science as a Process

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Assignment – Due Tomorrow

Beginning of Period

Section 1.2 Key Terms

End of Period

Directed Reading Handout – Science as a Process