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Glossary Term
A study in which the participants are assigned by chance to separate groups to evaluate treatments. The study also includes a control group, which is undergoing the same rigors of the study with placebo treatment or standard treatment. The trial can also be controlled by the addition of a test group to ensure there are no factors present to skew the results and by the inclusion of peer-review analysis by appropriate government officials. 2005
Glossary Term
A measure of the range of values in a set of numbers. Standard deviation is a statistic used as a measure of the dispersion or variation in a distribution, equal to the square root of the arithmetic mean of the squares of the deviations from the arithmetic mean.
Glossary Term
An established procedure to be followed in carrying out a given operation or in a given situation.
Glossary Term
A method for converting an individual score into a standard form. While similar to a z-score, t-score is used when the conversion is made without knowledge of the population standard deviation and mean.
Glossary Term
An alteration or difference from a norm or standard.
Glossary Term
A method for converting an individual score into a standard form. The z-score indicates how far and in what direction an item deviates from its distribution's mean, expressed in units of standard deviation. Calculation of a z-score requires knowledge about the population's standard deviation and mean.
