--- title: Reading Box Plots --- ## Reading Box Plots Box Plots might seem unintuitive at first glance, but they are a great way to convey a lot of information of a compact format. Here's how you can read the informations contained in a Box Plot: ![BoxPlotExample](https://github.com/viso-gio/HostedImages/blob/master/Boxplot.jpg?raw=true) The Box Plot has several elements that we can recognize: * The box, which is bisected in two parts * Two whiskers, above and below the box * Possibly some scattered points: the outliers Each section of the box plot represents the interval of a quartile of the population of data. What this means, is that 25% of the data lies within the two ends of the lower whisker, 25% within the interval spanned by the bottom of the box and the median line, 25% within the median and the top of the box, and 25% in the upper whisker. Any statistical outlier is represented as a point outside of the box. In the example reported above we would have (using approximate numerical values): * a quarter of the data between 1 and 3 (lower whisker) * a quarter of the data between 3 and 5 (lower part of the box) * a quarter of the data between 5 and 7.5 (upper part of the box) * a quarter of the data between 7.5 and 10 (upper whisker) * two outlier points above the boxplot Notice that the line that bisects the box represents the **Median** (50th percentile) and **not the Mean**. #### More Information: For more informations: * Wikipedia: Box Plot * Khan Academy: reading Box Plots(video)