VOCABULARY 1 Flashcards
Observational Study
A study based on data in which no manipulation of factors have been employed.
Experiment
Investigates how a response variable behaves when the researcher manipulates one or more factors to determine if changes in those factors cause changes in the response variable.
Retrospective
An observational study in which subjects are selected and then their previous conditions or behaviors are determined.
Prospective Study
An observational study in which subjects are followed to observe future outcomes.
Factor
A variable whose levels are controlled by the experimenter.
Response Variable
Values of this record the results of each trial with respect to what we were interested in.
Level
The specific values that the experimenter chooses for a factor.
Treatment
The process, intervention, or other controlled circumstance applied to randomly assigned experimental units.
Control Group
The experimental units assigned to a baseline treatment level, typically either the default treatment, which is well understood, or a null, placebo treatment.
The importance of random assignment
To be valid and avoid bias, an experiment must assign experimental units to treatment groups at random.
Replication
The practice of reducing chance variation by assigning each treatment to many experimental units.
Statistically Significant
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Single-Blind
When either subjects or the people who have contact with them do not know which treatment a subject has received.
Double-Blind
Neither the subjects nor the people who have contact with them know which treatment a subject has received.
Placebo/Placebo Effect
The tendency of many human subjects to show a response even when administered a fake treatment.
