Glossary Term
A statistical technique which helps in making inference whether three or more samples might come from populations having the same mean; specifically, whether the differences among the samples might be caused by chance variation.
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Glossary Term
The sum of a set of values divided by the number of values in the set.
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Glossary Term
The ratio of standard deviation to mean, expressed as a percentage or fraction.
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Glossary Term
The n-th root of the multiple products of n values, as contrasted with the normally understood arithmetic mean.
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Glossary Term
A family of probability density functions whose mean, median and mode are identical. The function generates a symmetrical curve, whose position and shape is determined by its location and scale parameters, the mean and standard deviation respectively. The standard normal distribution has a location parameter of 0 and a scale parameter of 1.
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Glossary Term
A statistical method to test if observations are significant or due to chance. It proposes that no statistical significance exists in a set of given observations and attempts to show that no variation exists between variables or that a single variable is no different than its mean. It is presumed to be true until statistical evidence nullifies it for an alternative hypothesis.
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Glossary Term
A method used to test whether the mean difference between pairs of measurements in a related group are significant.
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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.
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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.
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Glossary Term
A measure of the variability in a sample or population. It is calculated as the mean squared deviation (MSD) of the individual values from their common mean. In calculating the MSD, the divisor n is commonly used for a population variance and the divisor n-1 for a sample variance.
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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.
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