Data Brushing is a term applied to the visual linkage of observations, selected by the user, in one display to the same observations viewed in an alternative display. The technique was independently devised by Newton (1978) and, later, McDonald (1982). A key advantage of data brushing is that it affords the user a rich variety of displays, each optimised for a particular purpose (for example, a line chart for time series, a map for spatial patterns). Integrating such displays, via user interaction, allows rapid identification of patterns in quantitative data, which would otherwise remain hidden or time-consuming using just one isolated display. However, data brushing is largely regarded as an exploratory technique for expert users. More generally, data graphics, although widely used, are open to criticism of allowing users to see variation without context or explanation.
The concept of data brushing can be extended to include the use of textual narrative and multimedia content. Such an application has been developed and published by the UK Office for National Statistics to promote the 2011 Census in England and Wales. The graphic features an interactive dual histogram population pyramid, data table and bar chart together with text and audio commentary. By integrating traditional data displays with hyperlinked prose (and audio), users are able to identify statistical stories and instantly see the contextual impact of the story graphically.
Although an exploratory facility remains, the emphasis is firmly placed on user engagement and statistical literacy. As web content becomes increasingly immersive and interactive, techniques like data brushing can play a part in developing confidence using statistical interfaces. Looking forward, the ability of users to generate and share hyperlinked narrative could play a key role in popularising statistical graphics.
Keywords: Visualisation; Data brushing; Statistical literacy; Dissemination
Biography: Alan Smith is Principal Methodologist of ONS' Data Visualisation Centre. In recent years, he has created a variety of popular web-based data graphics, including animated population pyramids and interactive maps. A common theme of his work is exploring how the move from print to web provides new opportunities for producers of official statistics to engage with a wider audience. In 2010, he was the recipient of the inaugural Royal Statistical Society Award for Excellence in Official Statistics for his work on dissemination and communication.