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Flashcards in 2.3-2.5 Deck (15):
1

Experiment

A study in which one or more explanatory variables are manipulated in order to observe the effect on a response variable

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Explanatory Variables

Those variables that have values that are controlled by the experimenter. Also called factors.

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Response Variables

A variable that is thought to be related to the explanatory variable in an experiment. It is measured as part of the experiment, but it is not controlled by the experimenter.

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Experimental Condition

Any particular combination of values for the explanatory variables. Also called treatments

5

Extraneous Variables

A variable that is not one of the explanatory variables in the study but is though to affect the response variable.

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Random Assignment

(of subjects to treatments or of treatments to trials) to ensure that the experiment does not systematically favor one experimental treatment over another.

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Confounded

Two variables are confounded if their effects on the response variable cannot be distinguished from one another

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Blocking

Using extraneous variables to create groups (blocks) that are similar. All experimental conditions (treatments) are then tried in each block.

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Direct Control

Holding extraneous variables constant so that their effects are not confounded with those of the experimental conditions (treatments)

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Replication

Ensuring that there is an adequate number of observations for each experimental condition

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Control Group

During an experiment, including an experimental group that does not receive the treatment

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Placebo

Something that is identical (in appearance, taste, feel, ect) to the treatment received by the treatment group, except that it contains no active ingredients.

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Single Blind

An experiment in which subjects do not know what treatment they have received

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Double Blind

If subjects do not know which treatment was received and those measuring the response do not know which treatment was given to which subject

15

Experimental Unit

the smallest unit to which a treatment is applied