The steps to create this viz are as easy as 1-2-3:
Our team member Nick Hara kicked off the data-exploration effort by extracting the raw JSON file using Alteryx and Excel. After we prepped the data, the GSS Code (a unique nine-character alphanumeric administrative code) was available as a join field.
From there, I gathered geographic data sets from open-source data vendors. One data source came from the UK’s Ordnance Survey site, OS Data, where anybody can download the electoral divisions for Wales, Scotland, and England for free after signing into the website. I used OpenDataNI to obtain the 18 Parliamentary constituencies of Northern Ireland.
Once I gathered the different data sets, I simplified and merged the geographic data files to produce a seamless shapefile output. Then the data sets were loaded into my colleague Mary Solbrig’s extremely-handy TabShapeR tool to transform them into Tableau-readable geographic files.
Finally, since all of the geographic data sources contained the GSS code, the data easily joined to the processed JSON file that Nick had provided.
After that, it was time to visualize our voting data! Mary added some tooltips (and a handy side map to show the small-but-significant overseas territory of Gibraltar) and PRESTO—a custom-designed geographical viz was born!