Stem Plot

Introduction

A stem plot is a very simple way of visualising the distribution of values within a column. The “Stem” in the graph represents the largest magnitude component of the values, while the “leaf” represents the lowest magnitude. For example, in the range of values of 34, 45, 42, 48, 31, and 51, the stems would be 3, 4 and 5, (representing the stems of 30, 40, and 50),while the leaves would be the single digits: (3)4, 4(5), (4)8 (3)1 and (5)1

Inputs

To show the stem plot in action, we will look at some data in Western Australia

  •  Select Western Australia as your area
  •  Select Socio-economic variables by SLA for Australia as your dataset, and select the following attributes:
    •  sla code
    •  sla name
    •  % with a degree or higher qualification (2006)

Open the Stem Plot tool (Analyse → Tools → Charts → Stem Plot) and enter the parameters (shown below)

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  • Dataset Input: Socio-economic variables by SLA for Australia
  •  colName: % with a degree or higher qualification (2006)
  •  Chart Title: Stem plot of Percentage Population with Higher Degree (2006) WA SLAs
  •  Greyscale: unchecked

Once you have entered the parameters, click Add and Run

Outputs

Once you have run your tool, click on the Display button that appears on the pop-up dialogue box. This should produce a graph that looks like the image below

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We can see that the majority of SLAs in WA have a percentage of the population with a higher degree between 10.0 and 19.9% (76 SLAs), with 58 between 20.0 and 29.9%