Institute for Informatics and Digital InnovationEdinburgh Napier University

INFORMATION VISUALISATION

WHAT

What is Information Visualisation (IV)?

Visual encoding of abstract information to allow visual exploration /detection of patterns

Can be used in tandem with statistical approaches

WHY

Humans have a well-developed visual system, so take advantage of its pattern-detecting facilities

Also some people just don’t trust data until “they see it with their own eyes”, or are uncomfortable with statistical measures

WHY

Finding patternsMPG and Weight negatively correlated

Horsepower and Weight positively correlated

WHY

Finding outliers / errorsLow weight but rubbish fuel economy

DATA STRUCTURES

Information is abstract i.e. non-physically rooted

Examples include

Family trees

Share prices

Social networks

Tuple data

INTERACTION TECHNIQUES

IV applications allow users to interact with the data, as opposed to being static screenshots (cf GraphViz)

Common techniques beyond the basics include Filtering – removing, reordering and re-rendering

according to selected subsets of information

Linking – viewing the same data (and same filters) in different views

Focusing – visual effects such as non-linear focus+context and zoom to accentuate areas of the visualisation

Speed of response is vital, recommend < 50ms

INTERACTION TECHNIQUES

Filtering works on a data set by interactively reducing the number of items that fit in the selected set.

Here a house sale set of 30,000+ records is cut down to under 2,000 using the sliders on the columns.

INTERACTION TECHNIQUES

Focusing works by giving more space to items of interest, but still retaining the ‘context’ of the unselected objects.

Here the selected items in blue have increased in size.

INTERACTION TECHNIQUES

Linking works by having data viewed simultaneously in different visualisations

The linking may also apply to selections and filters

Linking is closely associated with MVC architectures for separating UI and Model data. Use the same model data in multiple UI components.

WHERE

Games Developers have two opportunities for using IV

In the course of their work Workflow analyses

Software dependencies

In the game Attractive effects

User attention

Eick et al – SeeSoft – Developer tracker - 1992

SOFTWARE VISUALISATION

Software visualisation – one of the first topics explored by visualisation researchers – fixing their own problems first

Telea & Auber – CodeFlows SVN Visualisation - 2009

Van Ham – Call Matrices – Method Call Graphs - 2003

SOFTWARE VISUALISATION

CHISEL group – Creole – Call & Method graph - 2007

Stand alone tools are very well, but integrating them into IDEs such as Eclipse makes them more useful (and more likely to be used)

Malnati – XRay – Package dependencies - 2008

LIBRARIES

Developing visualisations can be time-consuming

Developer Libraries Integrate common vis techniques into existing

programs / websites (Prefuse, InfoVis Cyberinfrastructure)

End User Libraries Drop data into visualisation (ManyEyes. Mondrian)

THE END

Some demos at the CISS Napier website

http://www.ciss.soc.napier.ac.uk/

Q’s