This is an example of a 3D scatterplot that we are developing to support schools in Trafford. Still in prototype phase, we will continue to add functionality, but figured we should make it available for people to comment / improve.
Each ball on the chart represents a primary school. It was as easy to do for the whole of Greater Manchester as it was just for Trafford, so we've done that, though schoools in the other nine authorities aren't loaded by default - click on the legend item to turn on that LA's data. When more than one LA's data is turned on, the colour of the balls indicates which Local Authority it belongs to. Hover over a ball to see which school it is.
Click and drag the chart to rotate it in space(!). Note that unfortunately, the chart is not rotatable on mobile devices.
To interpret the chart, there are three axes:
The y-axis, or vertical axis, represents attainment in the 2015 Key Stage 2 tests / assessments. The actual measure used is the percentage of eligible pupils in the school who achieved level 4 or above in Reading and Maths tests, and Writing teacher assessment.
The x-axis, or horizontal axis, represents the national 2015 IDACI rank of the school - from 1 to 32,844. This is an index of a collection of indicators designed to allow comparison of small areas, all related to Income Deprivation Affecting Children. 1 is the most deprived in this collection, and 32,844 is least deprived. We have taken the postcode of the school to report this figure, not the postcodes of children that actually attend the school - not a perfect measure, but a reasonable proxy for deprivation. For more information about IDACI and the indices of deprivation, you can view the interactive map on our site, or visit the official page on gov.uk.
The z-axis, or depth axis, is the total income per pupil of the school.
From a design point of view, it is generally accepted that 3-dimensional charts are bad - for example 3D bar charts made in Excel where perspective can lead to misinterpretation. We feel, however, that in this case where the chart is interactive and rotatable, the data can be explored and more meaning got from it.
Our plans for this chart include:
- Adding different indicators - such as average point score, or value added for example
- Adding different contextual elements - size of school, proportion of children with English as an additional language, etc
- Adding a search box that will highlight a point, so entering "Michael" will highlight all schools with "Michael" in the name
We think that this chart could be very useful for understanding the impact of different factors on school attainment. We also think that it could be useful in clustering schools - for benchmarking purposes, and for potentially supporting the school to school support elements of Trafford's Teaching School Alliance.
As always - please send us feedback and comments to help us make this work.
All data has been obtained from the 2015 Primary School Performance Tables, published on the Department for Education website. Some schools are missing, because they were missing data in the performance tables, either income or attainment. This did not affect any schools in Trafford.