Wednesday, June 15, 2011

learning from bad graphics

They say when it comes to understanding how to be a good people manager, you can learn perhaps as much from a bad boss (what not to do) as you can from a great manager (what to emulate). I have to think the same is probably true when it comes to honing one's data visualization skills.

A good visual display invites you in. It's straightforward to read and understand. It reveals something interesting. A bad visuals turn you off. It may look too complicated or messy. It's hard to figure out what's going on. It may also misrepresent the data.

A colleague forwarded an article from TechCrunch recently, Look At Who's Winning The Talent Wars in Tech, 6/7/11. (Perhaps the lack of concision in the title serves as an early warning of bad things to come.) The article discusses the flow of talent between tech companies. It includes the following visual:

To put it bluntly: I am not a fan of this visual. Beyond looking clunky, it's wasting precious space that could be visually informing but is not. How could we make better use of the space this graphic occupies to tell a visual story?

I think the biggest opportunity lost here is having a visual sense of the relative magnitudes of talent flow. Currently, all the arrows convey is directionality; we actually have to read the numbers to get a sense of relative magnitudes, which would probably be much more straightforward in a table than a visual (at least then all of the text would be uniformly horizontal so we could read it!). Scaling the arrows to reflect the relative magnitude of talent flow would solve this.

It would also be great if the size of the circles could represent something meaningful to add context and not just take up space (e.g. number of employees in the given organization). 

If the arrows and circles were scaled, it would give the audience a quick visual sense of what's going on, helping to focus attention to interesting pieces and make information easier to pull out of the visual. A program like Circos could work well for this (view related blog post).

I actually had been thinking of recreating the visual using Circos, but a quick calculation (from info I have exposure to in my day job) made me super suspect of the figures provided, so I decided not to spend my time graphing bad data. The information used in the TechCrunch visual was mined from a social networking job seeker website, so the underlying dataset is not ideal for getting to the information they are after. As one of my colleagues pointed out: this is like using Facebook data to figure out how many people delete MySpace profiles to join Facebook! 

Ah, what we can learn from things done poorly...


  1. Darn, too bad the data's messy, this would indeed be a great Circos opportunity. Another big strike against the chart: no source or even time period listed (the article specifies that Top Prospect included job changes from the past 2 years).

  2. Ignoring the underlying data issues, I actually like this chart. I find that having the circles and lines to be the same sizes makes it easier to read. The color and direction of the arrows is enough to tell you which companies are importing talent and which ones are exporting.

    Personally, I wouldn't suggest changing the size of the circles because, 1) I don't think the size of the companies is critical to the visual's story, and 2) making the circles proportional to the size of the company would create huge real estate issues on the graph. Microsoft has 89,000 employees; LinkedIn has 1,000. If number of employees is important, there is space below the company name in the circle.

    I like having the lines the same size because making them larger would cause them to intrude upon each other. Making them smaller would mean that you couldn't have the white text labels, which would lead to floating text that might be difficult to visually connect to the proper arrow. The chart has a nice symmetry that I would hesistate to disrupt.

    I grant that you could increase the accuracy of the chart with lines and circles of different sizes, but for me it would not improve the readability. We're all eager to tell as much as we can in a given space, but sometimes the need for simplicity involves a trade-off with informational value.

  3. I'm very late to this party but I just discovered this blog recently. I wanted to see if I could make this chart more clear just using Excel and a few text boxes and shapes. This is what I came up with: The colors are not fantastic but I'm hoping this shows which companies are making major gains and which ones are losing a lot of people. That's what seemed more interesting to me in the data.