Transcript Scientific Method - Lyndhurst School District

Scientific Inquiry
How to Use The Scientific Method
Simple Ideas Lead to Scientific
Discovery

http://ed.ted.com/lessons/how-simpleideas-lead-to-scientific-discoveries
Scientific Method
A blueprint for
experiment success.
What is the scientific method?
It is a simple method scientists use to
conduct an investigation.
 It is a way to ask & answer scientific
questions by asking questions &
conducting experiments.

I. Question/Problem

Ask a question about something
observed.
– Why?
– How?
– What?
Question to be solved.
 Must be about something measurable.

II. Research/Collect Information
Gather information by making
observations
 Conduct research using creditable
sources

III. Hypothesis
Educated guess about how things work.
 Prediction
 Use If, then statements

– If ____ [I do this], then _____ [this will happen]

Focus on one variable only.
IV. Experiment - overview
Design a fair experiment that tests your
hypothesis
 Determine variables:

– Independent (aka manipulated) variable:
what is being tested
– Dependent (aka responding) variable: what
is being measured
Experiment (con’t) – variable
examples



A scientist studies the impact of a drug on cancer. The
independent variable is the administration of the drug. The
dependent variable is the impact the drug has on cancer.
A scientist studies the impact of withholding affection on rats.
The independent variable is the affection. The dependent
variable is the reaction of the rats.
A scientist studies how many days people can eat soup until
they get sick. The independent variable is the number of days of
consuming soup. The dependent variable is the onset of illness.
Experiment (con’t) - accuracy
Change only one variable at a time.
 Record observations, not inferences

– Observations are made using tools or senses
– Inferences are assumptions based on those observations

Use a control or control group
– This is a group that has nothing done to it; it serves as a
standard used for comparison in an experiment.

In order for results to be valid, conduct
several tests.
Experiment (con’t) – recording data

Record your data in a data table.
– Numerical (quantitative) data should be organized
in rows and columns
– The variables must be included and clearly
labeled
– List the number of trials
V. Data Analysis

Reduce (analyze) the data
– Determine average (if applicable)
– Create graphs
– Look for patterns or relationships
VI. Conclusion

Include a summary of your experiment.
 State if your hypothesis was accepted or
rejected and explain why.
 If hypothesis is rejected, give possible
reasons for the difference between your
hypothesis and the experimental results.
 Suggest further research (if possible)