Which Model do I use?
This is a very constrained, simple table to help students decide what type of statistical modeling is appropriate for their research question and data set.
|Comparing||Dependent (outcome) Variable||Independent (explanatory) variable||Parametric Test (normally distributed data)||Non-parametric test (ordinal or skewed data)|
|Single Comparison Tests|
|Averages of two independent groups||Scale||Nominal (Binary)||Independent t-test||Mann-Whitney test/ Wilcoxon rank sum|
|Averages of 3+ independent groups||Scale||Nominal||One-way ANOVA||Kruskal-Wallis test|
|The average difference between paired (matched) samples e.g. test scores before and after a class||Scale||Time or Condition variable||Paired t-test||Wilcoxon signed rank test|
|The 3+ measurements on the same subject||Scale||Time or Condition variable||Repeated measures ANOVA||Friedman test|
|Relationship between 2 continuous variables||Scale||Scale||Pearson’s Correlation Coefficient||Spearman’s Correlation Coefficient|
|What is value of DV when value of IV changes?||Scale||Any||Simple Linear Regression||Transform the data|
|What is value of DV when value of IV changes?||Nominal (Binary)||Any||Logistic regression||NA|
|What is value of DV when value of IV changes?||Nominal (Count)||Any||Poisson Regression||NA|
|What is value of DV when value of IV changes?||Nominal (Count, overdispersed)||Any||Negative Binomial Regression||NA|
|Assessing the relationship between two categorical variables||Categorical||Categorical||NA||Chi-squared test|