QM #5
Exploring Assumptions

Homogeneity of Variance

💡 homogeneous

Residual

💡 The difference between the observed value of the dependent variable (y) and the predicted value (ŷ)

Skewness

💡 Unsymmetrical distribution

➖: Distribution tail on the right

➕: Distribution tail on the left

"N" > Whole sample

"n" > subsample within the whole sample

probability-probability plot (P-P plot)

quantile-quantile plot (Q-Q plot)

💡 a graphical technique for determining if two data sets come from populations with a common distribution. A q-q plot is a plot of the quantiles of the first data set against the quantiles of the second data set.

Measured using Levene's test

Categorical

Scale

Ordinal (order)

Nominal (arbitrary)

📝 Age group, etc.

📝 Likert scale questions (see Larson Hall, p. 53)

📝 Gender, marital status, etc.

Bar chart only

Bar or pie chart

Outliers