Box Plots

Box&Whisker - WolframAlpha

Box&Whisker – WolframAlpha

Box Plots show summary information for data – the box shows the median and quartiles and the whiskers are extended to all points which are not outliers.

A very clear description for younger students can be found on BBC Bitesize. For A Level Students the Centre for Innovation in Mathematics Teaching includes Box Plots in Chapter 3 of their Statistics text (page 26 of the pdf file, which is page 76 of the text).

Box Plots are particularly useful when comparing one or more distributions;

CIMT notes

CIMT Statistics Text

To help older students think further about about outliers and skew, have a look at this excellent illustration of Nobel Prize data from Plotly. Who is that outlier for the Nobel Peace Prize?!

Plotly - Nobel Prize winners by field

Plotly – Nobel Prize winners by field

Note that it is possible to display points with Box Plots in Plotly, the following data and charts demonstrates skew well:

Data

Box Plots & Skew

You can learn more about Plotly for graphing and sharing your data here: Learn and explore Plotly 

Statistics – WolframAlpha

A new slideshow has been added to the page demonstrating WolframAlpha syntax. WolframAlpha can be very useful for checking for example normal probabilities. Each query as you will see in the slides is illustrated with a diagram. It is always useful to sketch a diagram when solving any normal distribution problems.

Statistical Diagrams

Histograms from Waldo Maths

Do you know the difference between the various statistical diagrams?

A new page has been added to the Explore Series which includes several applets which will allow you to explore different diagram types.