Monthly Archive for August, 2008

Visualizaton Goals & Features

What are the goals of visualization? And what are the features that support those goals?

My 10 cents worth:

The basic goal is to facilitate reasoning and thought about what is being visualized. That reasoning could revolve around causality, hypothesis, predictions, inferences, habits, modus operandi, contradictions, uncertainty, and a whole host of problems the user is trying to solve. Often the reasoning revolves around external data and/or knowledge too. Visualization should expose structure in the data such as patterns, clusters, gaps, bursts of activity, outliers & trends, etc. And at the end of the reasoning process the great thing about visualization is that one should end up with a picture that can be used to disseminate one’s insights to other people.

So what key features enable these goals to be achieved?
* A Summarization/Overview to give the big picture
* Zoomability
* Drill-down on data for the detail
* Easy navigation around the visual
* Filtering information by category or query
* Different types of visualization expose different patterns (geographic, timeline, textual, lists, link diagrams, etc.)
* Brushing & linking visualizations together can help the filtering & exploration

Other basic things which must be in place in order to succeed:
* Ease of import and export – and adhering to any standards
* Some basic searching of the data
* One must be able to read the data – in particular any text
* Scaling well as the data size gets very large
* Links out to other systems for further information is key
* Links back in to the visualization from other systems can also be powerful
* Interoperability with other visualization tools and other applications in general
* Commentary, scribbling and drawing on the visualizations is a great way to add understanding – a picture alone is rarely enough

And don’t forget the more esoteric things too:
* It needs a positive emotional response so it must look good and not conflict with user’s expectations
* It can use standard visual symbolism, conventions & metaphors
* It must use the basic visual variables well (shape, colour, position, etc.)
* Transitions between visualizations must be smooth to allow the user to keep their context
* It should use design techniques like ‘information scent’ & obvious affordances
* It should facilitate playfulness where ever possible – don’t punish ‘mistakes’!

Phew – glad I got that off my chest – back to the day job :-)