When A Difference Actually Makes A Difference

Simple summary charts, like bar charts comparing two stores' customer satisfaction, can be deceptive by hiding crucial details about the underlying data. The same average difference can represent vastly different business realities depending on the data's variance and the sample size. Visualizing the full distribution with box-scatter plots and using statistical tests like ANOVA can help determine if an observed difference is statistically significant or just random noise. However, statistical significance alone is not enough, as effect size is needed to understand the practical magnitude and business importance of the difference. This distinction helps decide whether an observed gap is large enough to warrant a significant business investment.