This document discusses non-normal and bimodal distributions. It explains that non-normal distributions have bias or skewness, which can be caused by non-random sampling methods or processes influencing the results. The median is a better measure of central tendency for non-normal distributions. Bimodal distributions have two central tendencies, indicating observations from multiple populations. The document provides examples and instructs the reader to analyze sample data to identify normal and non-normal distributions using normality tests.