Statistical Techniques:

1. Statistical Techniques: KEY: GO! CAUTION! STOP! When to Use What VARIABLE’S LEVEL OF MEASUREMENT CH. TECHNIQUE NOMINAL ORDINAL DICHOTOMY RATIO 2 Frequency Distribution 2 Crosstabulation Too many categories? Mode 3 Does not exist. Median 3 Does not exist. Does not exist. Interpret as proportion. Mean 3 3 Standard Deviation Need a mean. Need a mean. Difficult to interpret. 3 Variance Need a mean. Need a mean. Difficult to interpret. Use standard deviation instead. 3 I.Q.V. Too many categories? Chi-Square Test 4 Need a mean. Need a mean. Use proportions C.I. 5 Confidence Interval 6 T-Test Need a mean. Need a mean. Use chi-square test. ANOVA Need a mean. Need a mean. Use chi-square test. 6 Use reference group technique. Possibly frowned upon. Make sure variable coded 0&1. 7 Regression I.V. Needs special technique. Needs special technique. Use logistic regression. 7 Regression D.V. No need to use this here. No need to use this here. Reference Groups I.V. 9 Use dichotomy and ratio var. Use dichotomy and ratio var. 12 Interactions I.V. Turn D.V. into dichotomy? Needs special technique. No need to use this here. 13 Logistic Regression D.V. Needs square of ratio variable. Needs square of ratio variable. Needs square of ratio variable. Non-Linear I.V. 15