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What statistical analysis should I use? The following table shows general guidelines for choosing a statistical analysis. We emphasize that these are general guidelines and should not be construed as hard and fast rules.  Usually your data could be analyzed in multiple ways, each of which could yield legitimate answers. The table below covers a number of common analyses and helps you choose among them based on the number of dependent variables (sometimes referred to as outcome variables), the nature of your independent variables (sometimes referred to as predictors).  You also want to consider the nature of your dependent variable, namely whether it is an interval variable, ordinal or categorical variable, and whether it is normally distributed (see What is the difference between categorical, ordinal and interval variables? for more information on this).  The table then shows one or more statistical tests commonly used given these types of variables (but not necessarily the only type of test that could be used) and links showing how to do such tests using SAS, Stata and SPSS. Number of Dependent Variables Nature of  Independent Variables Nature of Dependent Variable(s) Test(s) How to SAS How to Stata How to SPSS 1  0 IVs (1 population) interval & normal one-sample t-test SAS Stata SPSS ordinal or interval one-sample median SAS Stata SPSS categorical  (2 categories) binomial test SAS Stata SPSS categorical  Chi-square goodness-of-fit SAS Stata SPSS  1 IV with 2 levels  (independent groups) interval & normal 2 independent sample t-test SAS Stata SPSS  ordinal or interval         Wilcoxon-Mann Whitney test SAS Stata SPSS  categorical  Chi- square test SAS Stata SPSS Fisher's exact test SAS Stata SPSS 1 IV with 2 or more levels (independent groups) interval & normal one-way ANOVA SAS Stata SPSS ordinal or interval Kruskal Wallis SAS Stata SPSS categorical Chi- square test SAS Stata SPSS 1 IV with 2 levels (dependent/matched groups) interval & normal paired t-test  SAS Stata SPSS  ordinal or interval Wilcoxon signed ranks test  SAS Stata SPSS  categorical McNemar SAS Stata SPSS 1 IV with 2 or more levels (dependent/matched groups) interval & normal one-way repeated measures ANOVA SAS Stata SPSS ordinal or interval Friedman test SAS Stata SPSS categorical repeated measures logistic regression SAS Stata SPSS 2 or more IVs (independent groups) interval & normal factorial ANOVA SAS Stata SPSS ordinal or interval ??? ??? ??? ??? categorical factorial  logistic regression SAS Stata SPSS 1 interval IV interval & normal correlation  SAS Stata SPSS simple linear regression SAS Stata SPSS ordinal or interval  non-parametric correlation SAS Stata SPSS categorical simple logistic regression SAS Stata SPSS 1 or more interval IVs and/or 1 or more categorical IVs interval & normal multiple regression SAS Stata SPSS analysis of covariance SAS Stata SPSS categorical multiple logistic regression SAS Stata SPSS discriminant analysis SAS Stata SPSS 2 or more 1