The Scientific MethodThe Scientific Method

Earth SystemsEarth SystemsTuesday, April 18, 2023Tuesday, April 18, 2023

Key Elements of the Key Elements of the Scientific MethodScientific Method

ObservationsObservations Asking QuestionsAsking Questions Forming HypothesesForming Hypotheses Making PredictionsMaking Predictions Designing and Conducting ExperimentsDesigning and Conducting Experiments Drawing ConclusionsDrawing Conclusions

*There are several versions of the scientific method, but they all contain these key elements! Some have more or less steps.

ObservationsObservations

What is an What is an observationobservation??• Something perceived using the sensesSomething perceived using the senses• Can come from previous studiesCan come from previous studies

• ExampleExample: : When flying squirrels land on a tree, When flying squirrels land on a tree,

they quickly scramble to the other they quickly scramble to the other side.side.

Flying squirrels are temporarily Flying squirrels are temporarily blinded by bright light.blinded by bright light.

Asking QuestionsAsking Questions

Observations lead to Observations lead to questionsquestions• Problem to be solvedProblem to be solved

ExampleExample: Why does the flying squirrel : Why does the flying squirrel quickly scramble to the other side?quickly scramble to the other side?

Forming HypothesesForming Hypotheses

HypothesisHypothesis: a tentative : a tentative statement that can be tested by statement that can be tested by experimentationexperimentation

ExampleExample: The squirrel moves : The squirrel moves quickly to the other side to avoid quickly to the other side to avoid bright moonlight.bright moonlight.

Making PredictionsMaking Predictions

PredictionPrediction: an expected outcome : an expected outcome assuming the hypothesis will be assuming the hypothesis will be supportedsupported

ExampleExample: : If squirrels scramble to the If squirrels scramble to the other side to avoid bright moonlight, then other side to avoid bright moonlight, then we would expect squirrels landing on the we would expect squirrels landing on the dark side would not immediately move to dark side would not immediately move to the other side.the other side.

Designing & Conducting ExperimentsDesigning & Conducting Experiments

Control GroupControl Group: receives NO experimental : receives NO experimental treatmenttreatment

Experimental GroupExperimental Group: receives an : receives an experimental treatmentexperimental treatment• Differs from the Control Group by a Differs from the Control Group by a single single

factorfactor, the , the independent variableindependent variable• Dependent variableDependent variable-factor that depends on -factor that depends on

the independent variable; measured in both the independent variable; measured in both groupsgroups

Drawing ConclusionsDrawing Conclusions

Data collected from the experiment Data collected from the experiment is analyzed.is analyzed.

Does the data support your Does the data support your hypothesis?hypothesis?

A hypothesis is either A hypothesis is either supportedsupported or or rejectedrejected, , NEVER PROVENNEVER PROVEN..• Why?Why?

What next?What next?

Results from this experiment could lead to Results from this experiment could lead to new questions and the process starts all new questions and the process starts all over again!over again!

The Scientific Method is like a cycle.The Scientific Method is like a cycle.