PORTAL USER GUIDE
The histogram tool is a method that uses bars (or rectangles) to represent the distribution (such as the frequency, percentage, or proportion) of data by placing each data value in an appropriate class interval. It is useful for examining the spread of the dataset.
Each bar in the histogram represents a class of data. The independent variable consists of interval or ratio level data and is usually displayed on the x-axis and the frequency data on the y-axis with the height of the bar proportional to the count.
For this worked example, we will examine the spread of data for the Medicare Benefits Schedule’s (MBS) GP spend per capita across the Brisbane GCCSA in the 2016-2017 financial year.
Select the Greater Brisbane GCCSA as your area.
Select AIHW – Medicare Benefits Schedule Statistics – GP Attendances and Associated Medicare Benefits Expenditure (%) (SA3) 2010-2017 as your dataset, with the following variables:
- Financial Year (Filter value: 2016-2017)
- SA3 Code
- SA3 Name
- All GP Attendances – Medicare Benefits Expenditure Per Person Age-Standardised Rate
Once you have set up your data, open the Histogram tool (Tools → Charts → Histogram). The input fields are as follows:
- Dataset Input: The dataset containing the variables you would like to examine. Select AIHW – Medicare Benefits Schedule Statistics – GP Attendances and Associated Medicare Benefits Expenditure (%) (SA3) 2010-2017.
- Variable: The variable we would like to plot. Select All GP Attendances – Medicare Benefits Expenditure Per Person Age-Standardised Rate.
- Use Variable Titles: Check this box to use the variable’s names instead of the IDs on your output chart.
- Chart Title: Here we enter the title for the plot. In this instance, we have chosen MBS GP spend per capita in Brisbane GCCSA.
- Y-axis format: This allows us to choose how the Y-axis is formatted. The output histograms all look the same, but the y-axis can be formatted as density, frequency, percentage or proportion. Here we choose proportion.
- Grid: Select this if you want to choose grid-lines for your graph. Tick this box.
- Greyscale: Select this if you want your graph to be in greyscale, rather than in the default colour. Untick this box.
The input parameters are summarised in the image below, once complete click Run Tool.
Once the tool has run, click the Display button on the pop-up dialogue box that appears.
Your output should look something like the graph below. This indicates that the highest proportion of expenditure by the MBS on GP spending per capita is between $280 and $300.
Salkind, N. J. (2010). Histogram. In Encyclopedia of research design (Vol. 1, pp. 572–574). Sage.
Scott, D. W. (2010). Histogram. Wiley Interdisciplinary Reviews: Computational Statistics, 2(1), 44–48.
Venables, W. N., Smith, D. M., & Team, R. C. (1999). An introduction to R: Notes on R: A programming environment for data analysis and graphics Version 3.1. 0 (2014-04-10). R Core Team.