Scientific Method

ScienceScience is something you know and something you do.

Body of knowledge and getting answers about the natural world.

Pure science seeks to answer questions about how the natural world works.Applied science uses the information from the pure sciences to solve problemsEcology is the the study of how living things interact with each other and their nonliving environments.

Pure or AppliedPure • Applied

biology

physicsmedicineengineeringchemistry

environmental science

ecology

Scientific MethodObservationQuestionsHypothesisExperiment and Data CollectionSummarizing DataCommunicating Results

How it BeginsAll science begins with observations.

Use your senses: see, hear, smell, feel (not taste)Use instruments: X-rays, thermometers, etc.

Lead to QuestionsWhy, how, what if. . . Asking interesting questions is the basis of all science.

A Hypothesis is a testable explanation for the question or observation.

A possible answer that we can investigate

Good DesignNeed two groups

Experimental groupControl group

Only change one thing (variable)Everything else must be kept the same. Why?

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Studying WarblersTheory predicted that two species with identical ecological requirements would compete and push each other out.Observation: 5 species of very similar warblers live together in a northeastern spruce forest.Question:Hypothesis:

Ways to Test a HypothesisObservation

Benefits: In the field (natural environment), can observe natural behaviorLimitations: Hard to control experiment, hard to collect quantitative data

ExperimentBenefits: Can set-up and control experiment, focus on one thing to collect data from.Limitations: Not natural environment, can’t replicate all cases.

Modeling : using computer programs to predictBenefits: predict future or what if events, don’t disturb environment.Limitations: Must include as many factors as possible in model, hard to measure all components to include, lots of assumptions must be made.

Setting up an Experiment

Hypothesis is tested under controlled conditions.Two groups are studied

Only one variable changedAll other variables are controlled

Control group show what would happen with no treatment (normal)Why only change one thing?

Why ControlControl groups show us that the variable we are changing is truly causing the result.If we see the same result in both the control and experimental group what does that mean?If we change more than one variable we can’t tell which one is causing the result.

What to do with Data

Data is most useful when it has been organized and presented in easy to understand ways.Three main ways to organize data

TablesGraphs (line and bar for example)Pie Charts

Easier to see trends when presented

ExamplesObservation:Question:Hypothesis:Experiment:

And then . . . Scientist want to share their results . . .

To advance other discoveriesTo gain credit for their work

Publish results in scientific journalsPeer reviewedSearchable

Science builds on scienceLearn from past experimentsChange and update results as new information is available