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Scientific MethodScientific Method

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ObservationObservation Employing your five senses to

perceive objects or events

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Asking a Question Based on observations; one or

more questions are generated

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HypothesizingHypothesizing Explanation for what you have

seen and recorded Can be tested Based on prior knowledge

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Forming a HypothesisForming a Hypothesis Statement is testable if evidence

can be collected that either does or doesn’t support it

Often must be revised if it is NOT supported by the testing data

Often in the form of an “if-then” statement however doesn’t have to be.

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PredictingPredicting To test hypothesis it is necessary

to make predictions that logically follows from the hypothesis

A statement made in advance that states the results that will be obtained from testing the hypothesis

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ExperimentingExperimenting

Testing a hypothesis or prediction by gathering data under controlled conditions – conducting a controlled experiment

Based on a comparison of a control group with an experimental group

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Both groups are identical except for one factor (independent variable)

Observations and measurements are taken for a particular factor (dependent variable) in both groupsDriven by or results from independent variable

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Collecting DataCollecting Data Includes any and

all information that scientist gather in trying to answer their questions

Includes all measurements & observations made during the experiment

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MeasuringInvolves quantitative data that can be measured in numbers

SamplingTechnique of using a sample – a small part – to represent the entire population

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Organizing DataOrganizing Data Involves placing observations and

measurement (data) in order Graphs, charts, tables, or maps

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Analyzing DataAnalyzing Data

Collected and organized data must be analyzed Process of determining whether

data are reliable or whether they support or do not support a hypothesis or prediction

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InferringInferring Conclusions made on the basis of

facts or premises rather than on direct observations Often drawn from data gathered

from a study or experiment and previous knowledge

Not directly testable

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Forming a TheoryForming a Theory A theory may be formed

after many related hypotheses have been tested and supported with experimental evidence

A broad and comprehensive statement of what is thought to be true

Supported by considerable evidence

Ties together related hypotheses

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CommunicationCommunication Share the results of

their studies with other scientists

Publish findings in journals or at scientific meetings

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CommunicationCommunication Sharing of information is

essential to scientific process Subject to examination and

verification by other scientists

Allows scientists to build on the work of others

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Scientific Scientific MeasurementsMeasurements

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MeasurementsMeasurements Scientists use SI units or metric

system Based on units of ten

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Base Units of Measurement Length – Meter Volume – Liter Mass – Gram Time – Second Temperature - oC

Always read the Meniscus (bottom of the curve)

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Common Metric Prefixes Common Metric Prefixes used in Biologyused in Biology

Kilo- means 1000 Centi- means 1/100th

Milli- means 1/1000th

Micro – means 1/100,000th

Nano- means 1/100000000th

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Other Metric PrefixesOther Metric Prefixes

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