Free course

Interpreting data: Boxplots and tables

Free statement of participation on completion

This free course, Interpreting data: Boxplots and tables, is concerned with two main topics. In Section 1, you will learn about another kind of graphical display, the boxplot. A boxplot is a fairly simple graphic, which displays certain summary statistics of a set of data. Boxplots are particularly useful for assessing quickly the location, dispersion, and symmetry or skewness of a set of data, and for making comparisons of these features in two or more data sets. Boxplots can also be useful for drawing attention to possible outliers in a data set. The other topic, which is covered in Sections 2 and 3, is that of dealing with data presented in tabular form. You are, no doubt, familiar with such tables: they are common in the media and in reports and other documents. Yet it is not always straightforward to see at first glance just what information a table of data is providing, and it often helps to carry out certain calculations and/or to draw appropriate graphs to make this clearer. In this free course, some other kinds of data tables and some different approaches are covered.

Course learning outcomes

After studying this course, you should be able to:

  • understand and use the following terms: boxplots, box, whisker, upper and lower adjacent values, rate, time series, line plot
  • demonstrate an awareness of the idea that the general pattern of a set of data, in terms of location, dispersion and skewness, can be graphically represented in a boxplot
  • understand that boxplots can be used to provide a quick and simple comparison of data sets
  • understand that patterns in tabular data can be made clearer by leaving out unhelpful information, by including extra pieces of useful information, or by drawing appropriate graphs
  • describe and compare data sets on the basis of boxplots.