Thoughts on the original charts
The chart highlighted to Makeover Monday participants was a pie chart showing the proportion of works in the collection by Turner versus all other artists. It works well to illustrate a key point about the data and explain why the author excluded Turner’s works from a number of their beautiful visualisations; when Turner’s works are included they skew the data to the point where other artists can’t be seen. The Tate Collection includes the Turner Bequest of roughly 30,000 works of art. Many of these art works are unfinished or preparatory sketches – e.g. each page in a sketch book is counted as a separate work. Angie Chen’s submission explains this nicely and is well worth checking out along with the original article.
For the makeover I wanted to take on the challenge of showing Turner and other artists in the same viz, without skewing the data. I recalled various art timelines from school days and a Gantt chart seemed like a good way to achieve this. The Gantt chart would show the range of years for each artists work. And when the artists were ordered by start year it would have the feel of a timeline. I then experimented with overlaying semi transparent marks for the actual art works, the aim being to have a denser / more packed overlapping set of marks for Turner than other artists:
The timeline is also available on Tableau Public here, where you get the option to hover over and click a link to see an example piece of art.
There were still too many artists to show so I filtered the list to exclude art not attributed to a year and to focus on the top 25 artists which helped to keep the timeline concise. Highlighting the top 5 also helps the casual reader. Some fiddling around was needed to get labels formatted nicely when including the highlighting. I’ve just employed the usual trick of having two calculations returning a value or empty string in opposite circumstances.
Formatting the Gantt bars was probably the biggest challenge. A Gantt bar will stretch to a point and not beyond, whereas if you plot a shape at that same point it is centred on the point and extends past it by half of it’s size. I wanted to achieve a look where the Gantt bar was simply a box around the collection of points, so to start with I ended up with the start and end points spilling out of the box – definitely not the look I was after.
To get around the marks spilling out of the boxes I created additional calculations that extended the ends of the boxes by enough years to fix the formatting. Is this a fudge? Is it a bad thing to do? To an extent yes, because it misrepresents the data! But in its defence most viewers won’t get (or need?) an accurate idea of the specific start and end year on a first glance anyway, and the actual years are included in the hover over tooltip.
A few participants hit issues using the URLs included in the data set to pull in images of the art work. The conclusion seemed to be that the Tate site didn’t allow it’s content to be iframed. I didn’t try to tackle this and instead just provided a link to click through to some examples.
I think I’ve achieved my goal with the viz. If time allowed I’d work on the option to view the actual pieces of art and more details about them. I briefly toyed with producing ASCII versions of the art work for inclusion in my tooltips; hover over a mark to see the piece of art …. kind of! Could have been a good excuse to create a web data connector maybe. I also wondered whether I could have nested a spark line or histogram within he Gantt chart bars. No shortage of ideas with this weeks data!