Q-Q Plots and Shapiro-Wilk: Checking Normality in SPSS
Why Checking Normality Matters Before You Run a Test Almost every parametric test in SPSS — the independent-samples t-test, one-way ANOVA, Pearson correlation, linear regression — comes with a small-print condition: your data should be approximately normally distributed. Skip that check and you risk reporting a p-value from a test whose assumptions your data never