Scientific MethodsScientific Methods

Section 1.3Section 1.3

ObservationsObservations

Using the senses to gather informationUsing the senses to gather information

Scientific methods begin with observationsScientific methods begin with observations

Good observations lead to testable Good observations lead to testable predictionspredictions

Form a QuestionForm a Question

After making an observation, a problem or After making an observation, a problem or question is statedquestion is stated

The question is based on information that The question is based on information that you want to reveal about your you want to reveal about your observations observations

HypothesisHypothesis

Develop a testable predictionDevelop a testable prediction

A hypothesis is tested by conducting A hypothesis is tested by conducting experimentsexperiments

The hypothesis may be supported by The hypothesis may be supported by evidence but is never PROVEDevidence but is never PROVED

Gather DataGather Data

Includes all information that scientists Includes all information that scientists gathergather

Quantitative data= Measured in numbersQuantitative data= Measured in numbers (measurements, temperature, weight)(measurements, temperature, weight)

o Qualitative data= descriptiveQualitative data= descriptive

Conduct ExperimentConduct Experiment

A variable is tested and compared to a A variable is tested and compared to a control groupcontrol group

Experimental groupExperimental group= the group subjected = the group subjected to a specific factorto a specific factor

Control groupControl group= identical to experimental = identical to experimental group except for the factor group except for the factor

(used for comparison)(used for comparison)

VariablesVariables

Independent variableIndependent variable= the factor being = the factor being tested (example: fertilizer)tested (example: fertilizer)

Dependent variableDependent variable= the factor that is = the factor that is being measured (example: plant growth)being measured (example: plant growth)

The The dependentdependent variable results from the variable results from the independent variableindependent variable

Organize and Analyze DataOrganize and Analyze Data

Data should be placed in tables, charts, Data should be placed in tables, charts, and graphsand graphs

Statistical analysis determines whether or Statistical analysis determines whether or not the data supports the hypothesisnot the data supports the hypothesis

Form ConclusionForm Conclusion

Based on the conducted experiment, the Based on the conducted experiment, the results are summarized into a conclusionresults are summarized into a conclusion

Provides an explanation supported by dataProvides an explanation supported by data

Publish ResearchPublish Research

Valid experiments can be published in Valid experiments can be published in scientific journalsscientific journals

If proper protocol has been followed, even If proper protocol has been followed, even student research can be publishedstudent research can be published

InferencesInferences

Conclusions made on the basis of facts or Conclusions made on the basis of facts or premises rather than on direct premises rather than on direct observationsobservations

Example: where there is smoke, there Example: where there is smoke, there must be firemust be fire

Theories and LawsTheories and Laws

TheoryTheory= an explanation based on many = an explanation based on many observations supported by experimental observations supported by experimental results (example: theory of evolution)results (example: theory of evolution)

LawLaw= a rule of nature that sums up related = a rule of nature that sums up related observations and experimental results observations and experimental results

(example: law of gravity)(example: law of gravity)

Implementing Scientific MethodsImplementing Scientific Methods

Problem solving skills are used to solve a Problem solving skills are used to solve a wide variety of global problems such as wide variety of global problems such as human infectious diseaseshuman infectious diseases

Communication allows scientists to build Communication allows scientists to build on the work of others on the work of others