PSYC 2021 Lecture Notes - Lecture 4: Descriptive Statistics, Statistic, Squared Deviations From The Mean
12 Mar 2016
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Document Summary
Provides a quanitaive measure of the diferences between scores in a distribuion and describes the degree to which he scores are spread out or clustered together. Simply, if there are small diferences between scores then variability is small, if there are large diferences between scores, then variability is large. The purpose of measuring variability is to obtain an objecive measure of how the scores are spread out in a distribuion. A good measure of variability serves two purposes: variability describes the distribuion. It tells us whether the scores are clustered close together or spread out. Usually, variability is deined in terms of distance. This aspect of variability is important to inferenial staisics where small samples are used to answer quesions about populaions. Variability provides informaion on how much error to expect if you are using a sample to represent a populaion. Three diferent measures of variability range, standard deviaion, and the variance.
