MUED 6440 Ch. 3 Flashcards
The statistical test of homoscedasticity in multivariate situations
Box’s M test for equality of variance
Measured on a scale that changes smoothly over possible values rather than in steps; also referred to as interval or quantitative
Continuous variables
The application of mathematical procedures to data in order to make them appear more normal
Data transformations
The violation of the assumption of homoscedasticity
Heteroscedasticity
Assumption that the variability in scores for one continuous variable is roughly the same at all values of another continuous variable
Homoscedasticity
Tests the null hypothesis that the population is normally distributed
Kolmogorov-Smirnov statistic
Degree of peakedness of a distribution; equal to zero when a distribution is normal
Kurtosis
Condition when values for kurtosis are positive, indicating that the distribution is too peaked with long, thin tails
Leptokurtosis
A statistical test of the homogeneity of variances
Levene’s test
Assumption that there is a straight-line relationship between two variables
Linearity
Statistical measure of an outlier; distance of a case from the centroid of the remaining cases where the centroid is the point created by the means of all the variables
Mahalanobis distance
Cases with an unusual pattern of scores; values on individual variables may look reasonable, but the combinations of two variables produce values that look unusual or discrepant
Multivariate outliers
Assumption that all variables and linear combinations of variables are normally distributed
Normality
Cases with extreme values on one variable or on a combination of variables so that it distorts resulting statistics or unduly influence solutions or models; would result in an excessively large residual
Outliers
Condition when values for kurtosis are negative, indicating that the distribution is too flat, with many cases in the tails
Platykurtosis