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Non-parametric Statistics. EDRS 5305 Educational Research & Statistics. When to Use. Non-parametric statistics are used when: data are not normal (i.e., not normally distributed) assumptions inherent in parametric statistics are not met. Chi-Square.
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Non-parametric Statistics EDRS 5305 Educational Research & Statistics
When to Use • Non-parametric statistics are used when: • data are not normal (i.e., not normally distributed) • assumptions inherent in parametric statistics are not met
Chi-Square • A non-parametric technique used to analyze the results of research in which categorical data are present. • A most versatile and popular non-parametric method.
Chi-Square • Different types of chi-square tests but all deal with frequencies, proportions, or percentages. • Types are: chi-square goodness-of-fit test; chi-square test of homogeneity of proportions; and a chi-square test of independence.
Requirements for a Chi-square • Frequency data must be used (e.g., counts of persons or events) • Expected value in any cell should never be less than 5 • Sum of observed frequencies must equal the sum of the expected frequencies • Each score must be independent of every other score
Sample Research Question • What is the effect of gender on seating preference among college students? • In this question, gender is dichotomous, seating preference was a 5-item Likert question (front; left side; right side; middle; back). • Chi-square table would be a 2 x 5.
Sample Research Question • What is the effect of theoretical orientation on instructional units taught among classroom teachers? • In this question, theoretical orientation was categorical and instructional units taught was categorical.