The Methods of ScienceVocabulary

Problem StatementA statement to investigate a claim or the cause(s) or effect(s) of an observed phenomenon through experimentation.

Example 3: What effect does zero gravity have on bone density?

Example 2: What is causing the massive fish kill off of the Oregon coastline?

Example 1: Does Jolly fruit juice contain the 100% daily value of Vitamin C as claimed.

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Observations

Process of noticing and describing events or processes in a careful and orderly way.

Senses: Smell, Taste, Touch, Sight, Sound

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Inferences

Logical conclusions based on available information.

Observe

Infer

State Cause & Effect

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Rationale-based hypothesisBased on logical reasoning, it is a possible explanation for a set of observations that can be tested.

Fairy Rings

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Rationale-based hypothesisBased on logical reasoning, it is a possible explanation for a set of observations that can be tested.

H1: Cooler temperatures trigger the color change.

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H2: Decreasing daylight triggers the color change.

Observation: Leaves change color in the Fall, when daylight steadily decreases and temperatures get cooler.

Prediction

A statement of what outcomes to expect prior running an experiment.

Before After

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Counterintuitive result: Time to rethink the Hypothesis!

Null hypothesisThe proposition that implies any effect or relationship between phenomena is purely accidental and is not due to systematic causes.

Ho: There is no significant difference in the way boys and girls carry books.

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Manipulated VariableThe independent variable. The factor in a controlled experiment that is deliberately changed.

Fertilizer concentration

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What might be the manipulated variable?

Responding VariableThe dependent variable. The variable that is observed and changes in response to the manipulated variable.

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Rate of growth

What might be the Responding variable?

Controlled variablesAKA constants. Factors that do not change when other variables change.

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-type of container-amount of water-kind of soil-species of plant-amount of light-temperature

All of these samples have the same …

Controlled experimentAn experiment in which only one variable is changed.

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Fertilizer concentration

Experimental set-upAKA experimental group. The part of a controlled experiment which contains the manipulated variable.

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Mutant strain

Arabidopis seedlings

Normal strain

Control set-upAKA control group or experimental control: The part of an experiment that is exposed to the same conditions as the experimental set-up except for one independent variable.

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Mutant strain

Normal strain

Arabidopis seedlings

ProcedureA detailed, step-by-step set of directions to recreate the experiment for anyone.

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Experimental levelsThe values of a factor to be sampled in an experiment.

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How many levels are in this experiment?

Five: There appear to be five different levels or concentrations of fertilizer used.

TrialsThe act of running an experiment and collecting data.

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Look carefully. How many trials are in this experiment?

Two. There are two rows of pots.

ApparatusEquipment used in a laboratory or elsewhere for experiments or scientific study.

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UncertaintyThis refers to any error that can occur in an experiment.

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Parallax Sample sizeReaction time

Instrument precision

Instrument calibration

Quantitative dataData which can be measured and expressed as a number.

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Qualitative dataData which can be observed and described, but not measured.

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Data ProcessingThe process of using data to make calculations.

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Data PresentationDisplaying data in the form of tables and charts.

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Tables Charts

Experimental resultsDescribing trends and observations in data by comparing and contrasting charts.

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As time continues, what trend is evident?

ConclusionInterpreting data for cause and effect relationships. This involves accepting, rejecting, or modifying hypotheses.

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What conclusion can be made if the experiment below were based on a null hypothesis?

Air present Air removed

EvaluationAssessing the procedure and methods used, identifying sources of error, and suggesting modifications to improve the investigation.

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ModelUsed to represent an idea, an object, or event that is too big, too small, too complex, or too dangerous to observe and test directly.

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Too big

Too dangerous

Too complex

Too small

TheoryA well-tested explanation that unifies a broad range of observations and hypotheses, and enables scientists to make accurate predictions about new situations.

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Inactive TAS1R2 “Sweet tooth”

gene

House cat

10.8 mya

Cougar TigerLionBobcatCheetah

7.2 mya

6.7 myaCat

Evolution

Scientific LawA statement or description about what happens in nature that seems to be true all the time; does not explain why or how something happens.

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Laws of Motion Law of Gravity Laws of Planetary MotionLaw of Segregation

Law of Natural Selection

TechnologyThe application of scientific knowledge to solve practical problems, especially in industry and commerce.

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Ethics in Science29