Samples that include both independent and paired observations cause a dilemma for researchers that covers the full breadth of empirical research. Parametric approaches for the comparison of two samples using all available observations are considered, under normality and non-normality. These approaches are compared to naive and newly proposed non-parametric alternatives.
Derrick, B., White, P., & Toher, D. (2019). Parametric and non-parametric tests for the comparison of two samples which both include paired and unpaired observations. Journal of Modern Applied Statistical Methods, 18(1), eP2847. doi: 10.22237/jmasm/1556669520