qqplot

Understanding Empirical Cumulative Distribution Functions

What are empirical cumulative distribution functions and what can we do with them? To answer the first question, let’s first step back and make sure we understand “distributions”, or more specifically, “probability distributions”. A Basic Probability Distribution Imagine a simple event, say flipping a coin 3 times. Here are all the possible outcomes, where H […]

Understanding Q-Q Plots

The Q-Q plot, or quantile-quantile plot, is a graphical tool to help us assess if a set of data plausibly came from some theoretical distribution such as a Normal or exponential. For example, if we run a statistical analysis that assumes our dependent variable is Normally distributed, we can use a Normal Q-Q plot to […]