Monthly Archive for November, 2009

Visual Timelines and Narrative

The well-loved xkcd blog posted a great timeline sketch of film plots the other day.

xkcd movie timeline

It was noticed by the visualization & infographic blog community, and Walter Rafelsberger and Daniel McLaren did some nice follow up work, but for the most part people just seemed to be saying how cool it was and moving on.

I thought I’d try to put it into perspective.

Drawing narrative ‘persona’ lines along a timeline is a common technique.  The ‘persona’ usually represents a physical object – a person for example – and the vertical direction usually represents some sort of proximity.  Often geographic proximity.  Let’s see a few examples…

Marey’s train timetables (you can find them in the Tufte books) drew lines for each train:

Marey's Train Timeline from Tufte's Visual Display of Quantitative Information

From the physics world, Penrose diagrams are a concise depiction of space-time which allow event causality ‘cones’ to be plotted. Typically time runs bottom to top in these diagrams and observers are plotted as lines.

Penrose Diagram

This well-crafted musical visualization (pdf) from Jon Snydal & Marty Hearst has pitch as proximity, and the lines show structural patterns as the motif is repeated with variations:

Improviz Music Timelines

A few years ago, the BBC ran a programme about comedy heroes which I remembered for the credits and title sequences.  They show the interweaving careers of British comedians over the decades.

Here proximity represents collaboration on a TV program.

The wonderful JunkCharts blog showed this timeline narrative of Wall Street Bank acquisitions:

JunkChart's Wall Street Acquistions Timeline

And finally, a few years ago in the day job we put together a system for drawing out diagrams that can convey meetings and assignations:

Mumbai Attacks Timeline

What are the aesthetic and legibility rules that govern these kind of diagrams?  Are there rules similar to graph drawing aesthetics?

I think there are some guidelines.

  • Meetings, significant events, etc. can be shown as joining lines: most of the narrative power comes out of this simple drawing metaphor.
  • Other line crossings are to be avoided.
  • When they can’t be avoided,  use a good visual design to allow the eye to follow what is going on.
  • Make sure the line labels are legible across the diagram.  It isn’t any good just labelling the left side because by the time one has scrolled over to the right the labels will be out of view.  On a static picture this means repeating the label as in the xkcd example. Also consider labelling the right hand side too.
  • Colour is good for categories of persona.
  • Colour plays an important role in helping your eye distinguish between lines.
  • Thick lines are easier on the eye than thin ones.
  • Curved lines are preferable to straight lines – they are just easier to follow.
  • Lines can start late and end early.  If that line is a character in a movie, abrubt termination means the worst has happened ;-)
  • Line style can change as the story evolves and you can use this for narrative effect. In the xkcd Jurassic Park example, the dotted line shows a velociraptor is in prison.
  • Parallel lines work really well.

Perhaps the least talked about point in Manuel Lima’s manifesto was ‘Embrace Time’.  I agree with Manuel that we should be working on this and it would be great to see more effort in this area.