SELECTING A HYPOTHESIS TEST: a short decision program
Based on Robert S. Witte (1993) Statistics 4th Ed. New York: Harcourt Brace
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edited 10/14/05
Do each line in order, UNLESS OTHERWISE DIRECTED. Follow any instructions given. Answer the questions, if any, If your answer to a question is NO, drop to the next numbered line.
1. Qualtitative vs. Quantitative, i.e. are observations numbers?(1) If so, GO to 5.
2. Qualitive: Are observations cross-classified? If so GO to 4.
3. USE a One-Way Chi-squared Test. YOU ARE FINISHED.
4. USE a two-way Chi-squared Test. YOU ARE FINISHED.
5. Quantitive: Is there only one group? If so, USE t for one population mean. YOU ARE FINISHED.(2)
6. Quantitive: Are there only two groups? If not, GO TO 11. If so, are quantitative observations paired?
7. For unpaired observations (independent samples) , USE t for two population means. GO TO 13.
8. For paired observations (dependent samples), are they evaluated for a relationship? If so, GO TO 10.
9. No relationship, USE t for two population means. GO TO 13.
10. Relationship, USE t for population correlation coefficient. YOU ARE FINISHED.(2)
11. (Quantitative: Three or more groups. You will use F for ANOVA.) Are quantitative observations classified for two factors? If so USE two-way F test. YOU ARE FINISHED. (2)
12. Not classifed for two factors: Use one-way F-test. GO TO 13.
13. ADJUSTMENTS: Are original observations ranks? GO TO 15.
14. ADJUSTMENTS: Are basic assumptions violated? GO TO 15, otherwise YOU ARE FINISHED.
15. Use whatever are appropriate of the following tests:
Mann-Whitney U, Wilcoxon T, Kruskal-Wallis H YOU ARE FINISHED.
(See also R. Serotkin's Statistics Study Notes)
NOTES____________________________________________________
1. If you are using numbers in place of names, for example, the numbers on a football player's jersey, or groups in a school indicated by grade or section numbers, then these numbers represent categories, not quantities or ranks. Go to step 2.
2. It is not clear to me why Witte's chart (see Witte 1993 inside back cover) does not proceed to step 13 for this option. --EGR