7 Some caveats

Here are a few final points about using visualisation tools.

First, as more and more use is made of interactive chart components, it is worth bearing in mind that something that is informative as an interactive component may not be so useful if it is printed out. Just as you should always write for an audience, so you should always write for your medium, When designing a data display you should be mindful of what you want it to communicate and the situations in which you want it to be meaningful. For example, the interactive UK stock price charts on Yahoo! Finance [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] allow users to zoom in to different areas of the chart and explore them interactively. If it’s likely that an online document containing an interactive chart will be printed out, you may need to take care in configuring the chart (or the print template for the document) so that an appropriate view of the chart is displayed in the print version. Due consideration also needs to be paid to managing the expectations of the users. For example, if they use the interactive chart to display a particular view over the data and then print the document out, will the view they have selected be the one that gets printed out?

Second, one of the potential problems with using data from public data-sharing websites is that you can’t necessarily guarantee the accuracy, or authenticity, of any particular data set. To be sure of the provenance of the data, you need to either download from a trusted site for original data (such as the UK National Statistics website, the UK Government Data Repository, the World Bank, and so on) or go to a trusted third-party site that in some way guarantees the quality of the data. This is where sites like the Guardian Data store come in. Sites like these maintain directories of ‘qualified’ or otherwise trusted data, as well as curating data themselves. They may even support closely integrated visualisation tools.

And finally, but very importantly, if you do download the data yourself from a website, with the intention of re-using it, then there may be licensing issues that restrict what you can legally do with the data. Further, if you use data from a third-party source, you should always reference it in the same way that you would reference a book or journal article that you may have quoted.