1 Science as a Process Chapter 1 Section 2

2 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.

3 Goal of Science  To explain natural phenomena by asking questions about natural events and answer them through experimentation and examination.

4 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.

5 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.

6 Science Is A Method  An organized and logical approach to scientific research. The following are guidelines to problem solving.

7 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.

8 To Ask A Question  We often begin with observations, using the senses to gather information about the world. These lead to questions.

9 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.

10 Test The Hypothesis  Usually done by performing an experiment, a procedure that is carried out according to certain guidelines.

11 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.

12 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.

13 This Leads To  New questions, further study, new knowledge, and new methods of inquiry.

14 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.

15 Accuracy and Precision  Accuracy – How close a measurement is to the true value of the thing being measured.  Precision – The exactness of the measurement.

16 Accurate or Precise?

17 Purpose or Question “problem" Hypothesis Controlled Variable(s) (constant across treatments Responding Variable (measurement) manipulated Variable Procedure “methods” Prediction

18 Treatments  Appropriate levels (values) that you assign to the independent variable.  Examples?

19 Controlled Variable(s)  All independent variables other than the one being studied that are to be held constant.

20 Do we run the experiment now ?  NO!

21 A prediction needs to be made before you run the experiment. A prediction needs to be made before you run the experiment. What is a prediction?  A prediction is the expected result of an experiment (your “educated guess”). Usually it takes the form of an “if  then” statement.  Your prediction has to be based on your hypothesis.

22 Collect data. Collect data. What is data?  It is the actual results of your experiment. (not the character on Star Trek)

23 Form a conclusion. Form a conclusion. What is a conclusion?  A conclusion is a statement on whether your hypothesis is supported or not.  If your data = your prediction, then your hypothesis is supported.  If your data = your prediction, then your hypothesis is not supported.

24 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.

25 Models  A description, representation, or imitation of an object, system, process, or concept.  Many kinds (physical, graphical, conceptual, mathematical, computer, etc.).

26 Acceptance of Scientific Ideas  Conclusions are introduced to the scientific community and undergo review and testing before the ideas are accepted. Voltaire

27 Publication of Results and Conclusions  Results are commonly presented in scientific journals (written in a standard format) or at professional meetings. Galileo Galilei

28 Peer Review The 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.

29 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

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

31 Theories are NOT guesses!  They can be changed if conflicting information is discovered in the future.

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

33 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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35 Assignments  Section 1.2 Outline/Notes  Key terms  Direct Reading Worksheet  Wednesday –Accuracy Lab  Friday – Show N Tell EC