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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
The standard deviations of the sample in a frequency distribution, obtained by dividing the standard deviation by the square root of the total number of cases in the frequency distribution.
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.
