Random Etc. Notes to self. Work, play, and the rest.

Sticks and Rocks: Illustrating the Problem?

Over at Data Mining, Matthew Hurst takes exception to JC Herz's assessment of his map of the blogosphere as "(approx.) "completely useless"". Having recently engaged in several discussions about beautiful-but-useless visualizations I continue to insist that not everything has to be useful; perhaps Matthew doesn't intend for his map of the blogosphere to necessarily be useful in a traditional sense. That said, I have to admit that JC's blunt assessment is easy to agree with, and I had a similar reaction to the maps when I first saw them myself.

After the initial wave of early Google Maps mashups, some members of the mapping hacks community settled on the term "Red Dot Fever" (coined by Jo Walsh or Schuyler Erle, I think) to sum up the common patterns they were seeing. In a similar fashion (affectionate, but with a critical eye), my colleague Mike Migurski calls the prevailing network visualization technique the "Sticks and Rocks Diagram".

Matthew's images clearly have lots in common with the kinds of work catalogued meticulously at Visual Complexity. Sadly, I think a lot of the work there (some of my own included) is better at illustrating the problem than really informing us about the data that drives it. There's nothing intrinsically wrong with a popular approach to something, but when the results are so often misunderstood I bet we can all do better.

I've read a lot of research papers that would suggest that visualizing large complex networks is hard. Throwing the data at the screen and seeing what sticks is possibly a road to understanding, but I suspect it's an incredibly long one. Calling something "completely useless" doesn't drive our field forward or help open it up to new audiences, but the sentiment underpinning that reaction is something we could all work to understand better.

To me, red-dot-fever maps and sticks-and-rocks diagrams always look like works in progress.


6 Comments

I don’t understand the thing with people who do visualizations dissing each other rather than focusing on more constructive critiques. Is it tradition?

It’s ironic that Matthew got dissed on this, because he is pretty thoughtful on his blog about when and why to use different methods (for instance, this post on the Lehmann and Kottler graph layout). Hyperbolic view is not so good for 2d graphs, because it gets squashed on the sides, but he also publishes different angles of the sphere.

As I have seen them, network diagrams mostly serve two purposes:

1. To impress on someone with the scale/interconnectivity of a set of data.

2. Show some really basic clusters (the LinLog energy model, which Frank van Ham pointed me to, does this to a greater extent than the standard force model or Fruchterman-Reingold. Although it could be argued the extent to which it allows the creator to exaggerate clusters, especially if viewers are used to seeing the standard layouts)

If you add an interactive componenet, you can also show a little more. For instance, Moritz Stefaner has a flash applet where you can highlight correlations between nodes in a graph.

Posted by mike love on 8 November 2007 @ 6pm

Mike, if what I wrote comes across as dissing and not constructive critique then it’s because my writing is bad - I don’t want to get into mud-slinging territory. Sorry if it comes across that way.

I agree with the two purposes you’ve outlined. But both are dangerously close to merely “illustrating the problem” that I described above. I think we can all be more ambitious!

Sure, there are good tools available to take a dense network and draw a graph layout of it - but I’m asserting that those graph layouts often aren’t good, or even aren’t worth the effort. It isn’t the fault of the people who try them - me included! - but I think that for a dataset like Matthew’s blogosphere data it’s naive to try and display it all at once. I’m not dissing Matthew by calling him naive, I’m suggesting that we’re all naive! I think we need to filter and manipulate the data, and I think we need to pick our data very carefully - I talked a bit about this here a while back.

Moritz might be onto something, mainly because he doesn’t try to show everything all at once. There’s an exploration/experience component to his work that slows you down and, perhaps, hopefully helps you learn something. He still relies on an everything-layout that doesn’t necessarily do a good job (least important things in the middle? who expects that?) but it’s getting there. I certainly aspire to make tools as elegant and interesting as that, don’t get me wrong!

I’m paying keen attention to other folks who are making interactive tools because I think that exploration and direct manipulation are as key to understanding as the visualization. I think that’s where we’re still learning, and that’s why I say we can do better.

Posted by TomC on 8 November 2007 @ 9pm

I was looking for this link when I was writing the comment above, it’s definitely relevant. It turns out it’s on Matthew’s blog! Graph Visualization is Difficult, but is it Useful?

Posted by TomC on 8 November 2007 @ 9pm

Oh, I was refering to this JC Herz comment: “completely useless”. What you’ve put here definitely qualifies as constructive.

Posted by mike love on 9 November 2007 @ 7pm

We used to call it the old ‘words-on-sticks’ interface. Never seen one that turned out to be actually useful, despite the initial attraction, from the Plumb Design Visual Thesaurus onwards. Still, they’re works-in-progress, like you say.

Posted by Dan Hill on 12 November 2007 @ 12pm

[...] large graphs is hard, the usual Sticks and Rocks as Tom points out  is  bloody aweful. I am not sure how particular this is to graph, since my intution is that [...]

Posted by Sundry / Data Visualization on 7 December 2007 @ 3am