PSY 2402: Ch.3

skewness

Measures of this tell you whether a distribution is symmetrical or asymmetrical

Mu

The mean of a population

central tendency/ average

The most important property of data; the score value on which a distribution centers.

parameter

a descriptive measure for a population

statistic

a descriptive measure for a sample

interpolating

dividing the class interval containing the median into subintervals and finding the point that represented the (n+1)/2th score or the point that was midway between the n/2th and (n/2)+1th scores.

kurtosis

measures of this tell you whether a distribution is peaked or flat.

median (Mdn)

the point in a distribution that divides the data into two groups having equal frequency.

mode (Mo)

the score or qualitative category that occurs with the greatest frequency; The simplest of the three conceptions of central tendency; most often used for qualitative variables.

mean

the sum of scores divided by the number of scores; The most widely used and familiar measure of central tendency

dispersion

which is the extent to which scores differ from one another—that is, their scatter or hetero-geneity