Applying appropriate statistical testing 

Parametric tests (t-test, ANOVA, ANCOVA)

Non-parametric tests (Wilcoxon Signed-Rank, Mann-Whitney U, Kruskal-Wallis, Friedman and Sign Test)

Using parametric and non-parametric tests for prediction

Pearson correlation, linear regression, logistic regression, multivariate regression 

Spearman correlation, chi-square

Using tests to determine reliability, validity, sensitivity and objectivity

Internal Consistency Reliability (Cronbach α) 

Construct Validity (Factor Analysis) and convergent validity (correlation with other measures of the same construct) 

Floor and Ceiling Effects 

Inter-Rater Reliability