SCIENTIFIC METHODSCIENTIFIC METHOD

By By

Dawn M. ThompsonDawn M. Thompson

Scientific MethodScientific Method

Developed by Galan in 2nd Century A.D.Developed by Galan in 2nd Century A.D.

Series of steps followed by scientists to solve Series of steps followed by scientists to solve problemsproblems

1. DEFINE PROBLEM1. DEFINE PROBLEM

State the problem in the form of a question to be State the problem in the form of a question to be answeredanswered

2. RESEARCH PROBLEM2. RESEARCH PROBLEM

1. Making observations1. Making observations 2. Making initial measurements (quantitative)2. Making initial measurements (quantitative) 3. Collect information from different sources3. Collect information from different sources

3. HYPOTHESIS3. HYPOTHESIS

Form a Form a hypothesishypothesis (educated (educated guess).guess).

Make a prediction to answer Make a prediction to answer problem.problem.

Experiment are performed to Experiment are performed to testtest the hypothesis which may the hypothesis which may be supported or refuted.be supported or refuted.

4. EXPERIMENT4. EXPERIMENT

Experiments test the hypothesis.Experiments test the hypothesis.

Variables: any factor that may influence the Variables: any factor that may influence the experimentexperiment

Control: a standard for comparisonControl: a standard for comparison

Only Only ONE ONE variable may be tested at a time.variable may be tested at a time.

SafetySafety

CONTROLLED EXPERIMENTCONTROLLED EXPERIMENT

Experiment based on the comparison of a control Experiment based on the comparison of a control group and an experimental groupgroup and an experimental group

VARIABLESVARIABLES

All variables in an experiment All variables in an experiment are the same except for are the same except for oneone factorfactor

Independent variable:Independent variable: the the manipulated variable (manipulated variable (II change change it)it)

Dependent variable:Dependent variable: the factor the factor that is being that is being measuredmeasured or or controlledcontrolled duringduring the the experiment.experiment.

5. DATA COLLECTION5. DATA COLLECTION

Observe and record data from experiment. Observe and record data from experiment.

Present data in charts, graphsPresent data in charts, graphs

6. CONCLUSIONS6. CONCLUSIONS

Draw conclusions by inferring a resolution Draw conclusions by inferring a resolution based on the facts.based on the facts.

Determine whether the hypothesis is supported Determine whether the hypothesis is supported or refuted.or refuted.

7. REPORTING7. REPORTING

Accurately report research Accurately report research methods, results and methods, results and conclusionsconclusions

Modeling - a visual, verbal Modeling - a visual, verbal or mathematical or mathematical representation of an objectrepresentation of an object

Communication methods: Communication methods: make a presentation, publish make a presentation, publish in a journal, share data with in a journal, share data with other scientists verbally.other scientists verbally.

8. THEORY8. THEORY

A hypothesis that is supported byA hypothesis that is supported by experimentalexperimental

evidence over a long period of timeevidence over a long period of time

Scientific explanations are based on fact and Scientific explanations are based on fact and

observation not superstition or fiction.observation not superstition or fiction.

KINDS OF RESEARCHKINDS OF RESEARCH

Pure Science Pure Science - - for sake of knowledge for sake of knowledge

Applied Science (technologyApplied Science (technology)) - research to - research to solve practical problems; practical use of solve practical problems; practical use of acquire knowledgeacquire knowledge

Quantitative - numerical involves measuringQuantitative - numerical involves measuring Qualitative – descriptive: color, texture etcQualitative – descriptive: color, texture etc

SCIENCE AND SOCIETYSCIENCE AND SOCIETY BioethicsBioethics - the study of what is right and wrong and - the study of what is right and wrong and

morality of choices related to biological issuesmorality of choices related to biological issues 1. evolution - creationism vs. evolutionism1. evolution - creationism vs. evolutionism 2. genetic engineering - how far can we go?2. genetic engineering - how far can we go? how far should we go?how far should we go? 3. AIDS - education, prevention, treatment3. AIDS - education, prevention, treatment 4. abortion - as a means of saving a life, a4. abortion - as a means of saving a life, a means of contraceptionmeans of contraception

Based on opinion. Based on opinion. SocietySociety decides what is considered ethical. decides what is considered ethical.

TOOLS OF THE BIOLOGISTTOOLS OF THE BIOLOGIST

General lab equipmentGeneral lab equipment Microscope: magnifies objectsMicroscope: magnifies objects Ultacentrifuge: spins mixtures separating cell partsUltacentrifuge: spins mixtures separating cell parts Chromatography: separates of mixtures of pigmentsChromatography: separates of mixtures of pigments Electrophoresis: separates substances in a mixture by the Electrophoresis: separates substances in a mixture by the

speed at which they move when subjected to an electric speed at which they move when subjected to an electric current. current.

Scientific sampling - collecting small samples to represent Scientific sampling - collecting small samples to represent an entire populationan entire population

Computer - record and coordinate large amount of data in Computer - record and coordinate large amount of data in order to make correlations in dataorder to make correlations in data