Nature of Science/Scientific

Method Unit 1

What Is Science?

The goal of science is to:– investigate and understand the natural world– explain events in the natural world– use those explanations to make useful

predictions

In short, science is an organized way of using evidence to learn about the natural world.

Questions to ConsiderQuestions to ConsiderHow can we determine if something is fact or opinion?How can we determine an answer to a problem?

ANSWER…THE SCIENTIFIC METHOD!

Step 1Step 1Ask a QuestionAsk a Question

- - define the problemdefine the problem - make sure only one problem is being studied- make sure only one problem is being studied based on your observationbased on your observation - observations are made by using your 5 - observations are made by using your 5 sensessenses

touchtouch tastetastesmellsmell sightsighthearinghearing

Step 2Step 2Research the problemResearch the problem– use all available resources to collect data on use all available resources to collect data on

the subject being covered.the subject being covered.– Ex: library, internet, books, magazines, Ex: library, internet, books, magazines,

interviews, etc.interviews, etc.

Step 5Step 5

Develop a Hypothesis Develop a Hypothesis -- educated guess-- educated guess

– make it a short and definitive statementmake it a short and definitive statement– it should be in “If….” “Then….” formatit should be in “If….” “Then….” format– the “if part” = the hypothesisthe “if part” = the hypothesis– the “then part” = is what you think the results the “then part” = is what you think the results will be at the end of the controlled will be at the end of the controlled experiment.experiment.– hypothesis can be changed.hypothesis can be changed.

Step 4Step 4Develop a Controlled ExperimentDevelop a Controlled Experiment

– contains only one experimental variable, known as the manipulated variable. I.E. the thing being tested

– Everything else in the experiment or all other variables must be the same.

– called constant variables– keeping these the same allows the

experimenter to show that it was the experimental variable that caused

the results.

Variables in a Variables in a Controlled ExperimentControlled Experiment

Manipulated Variable: variable are testing; also independent variable

Control Set-UpControl Set-Up: what you compare to, without manipulated variable

Responding Variable: variable you measure; dependent variable

Constant Variables: consistent between all trials

Step 5Step 5Record and analyze the dataRecord and analyze the data– the data may or may not support the the data may or may not support the hypothesis. hypothesis. – if the data proves the hypothesisif the data proves the hypothesis wrongwrong, change , change

the hypothesis, the hypothesis, notnot the data. the data. – if the data if the data supportssupports the hypothesis, additional the hypothesis, additional experimentation must then take place to build experimentation must then take place to build documentation concerning the documentation concerning the problem. problem.

Types of DataTypes of DataQuantitative Data

- expressed as numbers - obtained by counting or measuring - Ex: 50 ml, 800 km, 45 sec

Qualitative Data - descriptive - Ex: clear, spherical, smooth

Step 6

Draw A Conclusion

- use the evidence to support

or refute the hypothesis

- a proven hypotheis must

stand up to additional testing

- scientists test (repeat each

others investigations

Example:

Problem: Is Raid the best insecticide on the market?Research: Look up information on insecticides– what are the active ingredients, how many insects will it kill, how much does it cost, etc, etcHypothesis: Raid is the best insecticide on the market. If used, then it will kill insects 30% faster than other insecticides.

ExperimentExperiment: : – Spray 5 plates with equal amounts of Spray 5 plates with equal amounts of

different insecticides. different insecticides. – Cover each one with the same type and size Cover each one with the same type and size

of glass. of glass. – Add equal amount of the same type of Add equal amount of the same type of

insects and place them side by side and time insects and place them side by side and time the results.the results.

Collect data and analyzeCollect data and analyze: This is done by writing down : This is done by writing down the # of insects that died or how fast they died and then the # of insects that died or how fast they died and then organizing that information into a graph so you can organizing that information into a graph so you can better see what happened in the experiment.better see what happened in the experiment.

ConclusionConclusion: This is done after the data from the : This is done after the data from the experiment has been collected and analyzed. In this experiment has been collected and analyzed. In this step you will find out if you were correct and Raid was step you will find out if you were correct and Raid was the best or if your hypothesis was rejected!the best or if your hypothesis was rejected!

ComparativeComparative

Discovery/ResearchDiscovery/Research

ExperimentalExperimental