chi-square (non-parametric stats)

what are non-parametric tests used for?

categorical or ordinal data, does not meet normality assumptions

what does a chi-square test measure?

the relationship between two categorical variables, compares observed frequencies to expected frequencies

what does goodness of fit mean?

compares observed frequencies to expected frequencies

what does a X² goodness of fit test measure?

if sample data fits a specific distribution

what does a X² test of independence measure?

if two categorical variables are related

how is df measured for goodness of fit?

df = K-1

how is df measured for test of independence

df = (number of rows - 1) x (number of columns - 1)

what is a mann-whitney test?

compares two independent variables on an ordinal outcome

what is a Kruskallis-Wallis Test

compares three or more independent groups on an ordinal outcome