It is of the utmost important for any student beginning the study of statistics to understand the concept of variability. As any researcher knows, the process of science seeks to answer questions, from this perspective, science seeks to explain variability. The concept of within group variability helps students understand why measures of “spread” are such a critical building block for all future work in statistical study.
Now Susie can understand the conclusions around the variability in the low dose aspirin study. She also has enough knowledge of effect sizes to understand that parsing out the impact of sample sizes across many studies revealed that the actual impact of the variability is very small. While the issue of low dose aspirin may not be solved, the blanket acceptance of this as a preventative measure is now looked at through a different lens, thanks largely to the important work of statisticians in our world!