Geoff Ellis

Geoff in Florence, 2003

email:
tel: +44 (0)1524 510340
room: C20
post:
InfoLab21
South Drive
Lancaster University
Lancaster LA1 4YW UK

Computing department website

and counting!

Geoff in Pisa, 2003

Research

My main interest is in the area of information visualisation and in particular use of random sampling as an effective technique in visualising large datasets which often result in saturated (or cluttered) visualisations. The Sampling Lens has been developed as a testbed visualisation to investigate issues relating to sampling (thanks to Enrico Bertini from Rome who helped get the initial version off the ground). The Sampling Lens adopts the widely used lens metaphor to provide the user with a method to reduce the clutter in a resizeable, moveable region of scatterplots or parallel coordinate plots and this was sucessfully demonstrated at CHI 2005 in Portland, Oregon. Further developements include an investigation into automatic clutter reduction within the lens - this has required methods of actually measuring the clutter, to be designed and implemented (estimating the density of crossing lines as in parallel coordinate plots has been challenging! - subject of AVI and INFOVIS papers)*. See some photos from the AVI conference in Venice.

InfoVis 2007 in Sacramento was really good - nice weather, pleasant company, good food (apart from a veggie burger from hell) and a well organised conference with great keynotes. Take a look at our paper which takes an analytical criterion approach to classifying clutter reduction techniques for information visualisation.

Current projects:

Sampling structured data

Visualising uncertainty

Recent work:

A taxonomy of clutter reduction techniques ... presented at InfoVis'07

Have implemented an OpenGL version of the Sampling Lens for parallel coordinates, and added a cool 'Reality Check' fade and 'twinkling'. Can now also play with v. large datasets!

Investigated using a database back-end to the visualisation.

Rainbow parallel coordinates is a method of showing distribution of one of the attribute values (in rainbow colour) across other attributes. Works nicely with the sticky 'attribute' lens.

OpenGL version of the Sampling Lens for scatterplots gave rise to more issues.

As a offshoot of sampling, I've built prototypes to study 2 novel visualisations of Web site usage. The Quantum Web Field clusters page-to-page links according to their popularity and visualises these as probability distributions. Actual paths through the site by current visitors can then be superimposed on the site to provide a sense of presence or awareness to the viewer. The associated application, the Molecular Meanderer uses the same data (extracted from Web logs by the way) but uses a more familiar ball-spring visualisation technique arranging the page links by "what page is usually taken after me" rather than the structure of the site. *

* Check out Alan Dix's page .... >

Previous work (whilst at Huddersfield Univ) - Interfaces to databases for effective information retrieval (HIBROWSE and VUSE) as part of CeDAR (Centre for Database Access Research).

Posters

The Sampling Lens poster as featured in the InfoLab21 Demonstrator Project	the plot, the clutter, the sampling and its lens: occlusion measures for automatic clutter reduction - AVI'06	The Sampling Lens: Making Sense of Saturated Visualisations - CHI'05	Quantum Web Fields and Molecular Meanderings: Visualising Web Visitations - AVI'04

medium large (5.8MB pdf)	medium large (2.5MB pdf)	medium large (1.3MB pdf)	medium large (0.2 MB pdf)

Recent Publications

Ellis G P. and Dix A. A Taxonomy of Clutter Reduction for Information Visualisation. IEEE Trans. on Visualization and Computer Graphics (Proc. Visualization/Information Visualization 2007), Vol.13, No.6, Nov/Dec 2007, IEEE, pp.1216-1223 (presented at InfoVis'07) eprint

Ellis G P. and Dix A. Enabling Automatic Clutter Reduction in Parallel Coordinate Plots. IEEE Trans. on Visualization and Computer Graphics (Proc. Visualization/Information Visualization 2006), Vol.12, No.5, Sept/Oct 2006, IEEE, pp.717-723 more info

Ellis G P. and Dix A. An Explorative Analysis of User Evaluation Studies in Information Visualisation. Proc. 2006 Conference on Beyond Time and Errors: Novel Evaluation Methods For information Visualization (BELIV'06), Venice, Italy, May 2006, ACM Press, pp.1-7 link to papers more info

Ellis G P. and Dix A. the plot, the clutter, the sampling and its lens: occlusion measures for automatic clutter reduction. Proc. International Working Conference on Advanced Visual Interfaces (AVI'06), Venice, Italy, May 2006, ACM Press, pp.266-269 more info, poster, eprint

Ellis G P., Bertini E. and Dix A. The Sampling Lens : making sense of saturated visualisations. CHI 2005 Extended Abstract, Late Breaking Results: Posters, Portland, Oregon, USA, April 2005, ACM Press, pp.1351-54 abstract and references, poster, eprint

Ellis G P and Dix A Visualising Web Visitations: a probabilistic approach. Proc. Information Visualisation 2004 (IV'04), London, July 2004, IEEE, pp.599-604 more info

Ellis G P. and Dix A Quantum Web Fields And Molecular Meanderings: Visualising Web Visitations. Proc. International Working Conference on Advanced Visual Interfaces (AVI'04), Italy, May 2004, ACM Press, pp.197-200 outline and links, poster

Ellis G P and Dix A Density control through random sampling : an architectural perspective. Proc. Information Visualisation 2002 (IV'02), London, July 2002, IEEE, pp.82-90 abstract and references

Dix A and Ellis G P. by chance: enhancing interaction with large data sets through statistical sampling. Proc. International Working Conference on Advanced Visual Interfaces (AVI'02), L'Aquila, Italy, May 2002, ACM Press, pp.167-176 abstract, contents and references, eprint

Pollitt A S, Ellis G P and Hosch I. Improving search quality using thesaurus for query specification and the presentation of search results.10 Years Anniversary Festschrift. ISKO - International Society for Knowledge Organization 1989-1999. Ed: Winfried Schmitz-Esser. Pub: ERGON-Verlag. November 1999

Dix A and Ellis G P. Starting Simple - adding value to static visualisation through simple interaction. Proc. International Working Conference on Advanced Visual Interfaces (AVI'98), L'Aquila, Italy, May 25-27 1998, ACM Press, pp.124-134. See abstract and outline

Teaching

Group Project co-ordinator for CSc240 - Software Design & Project Skills [2004-2007]

Assisting with HCI [2005/06]

Assisting with CSc243 - Databases [2004/05]

In a previous incarnation (at Huddersfield Univ), I ran courses on such topics as Information Visualisation, Computer Networks, Database Systems, Database Modeling, Program Design, Computer Systems Architecture

Almost the end note

Interested in traffic signs? ... probably not but you might like to see photos of what must be unique pedestrian crossing signs from the little island of Mauritius.

Some favorite activities: travelling in interesting places with Devina, relaxing on small islands in the indian ocean, growing veg. in my polytunnel, house construction, mountain biking, skiing, baking, light engineering (fixing cars and small tractors).

Other Publications

Pollitt A S, Treglown M, Smith M P, Braekevelt P A J, Ellis G P, Finlay J E and Wade S J.Empowering Users for Improved Database Access and Analysis through the Application of Knowledge Structure Views, Progressive Refinement Techniques and a Design Approach Driven by Usability. Proc. Fourth International ISKO Conference 15-18 July 1996 Washington DC USA (Ed: R. Green) Advances in Knowledge Organisation Vol 5 (1996), Pub: Indeks Verlag, pp 231-241

Pollitt A S, Ellis G P and Smith M B HIBROWSE for Bibliographic Databases. Information Science, Vol 20 No 6, December 1994, pp 413-426

Pollitt A S, Smith M P and Ellis G P Peek-a-Boo revived - End-user searching of bibliographic databases using filteringviews. Online 94, 18th International Online Information Meeting, London, December 1994, pp 63-74

Ellis G P and Lund G R. G2- A Design Language to help novice C programmers. 2nd All Ireland Conference on teaching of Computing, Dublin City University, Dublin, September 1994

Pollitt A S, Smith M P and Ellis G P. Using the thesaurus to view and filter environmental databases: An example using EUROVOC to search EPOQUE - the European Parliament Online Query System. First European ISKO Conference on Environmental Knowledge Organisation and Information Management, Bratislava, Slovakia,14-16 September 1994

Ellis G P, Finlay J E and Pollitt A S. HIBROWSE for Hotels: bridging the gap between users and system views of a database. Proc. 2nd International Workshop on User Interfaces to Database Systems, Lancaster, UK, Pub: Springer-Verlag Workshops in Computer Science, July 1994, pp 49-62

Pollitt A S, Ellis G P and Hosch I. Improving search quality using thesauri for query specification and the presentation of search results. Proc. Third International ISKO Conference, Copenhagen, Denmark, June 1994 Advances in Knowledge Organisation Vol 4 (1994), pp 382-389

4 publications prior to 1994

Last update : May 2008

	Ellis G P. and Dix A. A Taxonomy of Clutter Reduction for Information Visualisation. IEEE Trans. on Visualization and Computer Graphics (Proc. Visualization/Information Visualization 2007), Vol.13, No.6, Nov/Dec 2007, IEEE, pp.1216-1223 (presented at InfoVis'07) eprint
	Ellis G P. and Dix A. Enabling Automatic Clutter Reduction in Parallel Coordinate Plots. IEEE Trans. on Visualization and Computer Graphics (Proc. Visualization/Information Visualization 2006), Vol.12, No.5, Sept/Oct 2006, IEEE, pp.717-723 more info
	Ellis G P. and Dix A. An Explorative Analysis of User Evaluation Studies in Information Visualisation. Proc. 2006 Conference on Beyond Time and Errors: Novel Evaluation Methods For information Visualization (BELIV'06), Venice, Italy, May 2006, ACM Press, pp.1-7 link to papers more info
	Ellis G P. and Dix A. the plot, the clutter, the sampling and its lens: occlusion measures for automatic clutter reduction. Proc. International Working Conference on Advanced Visual Interfaces (AVI'06), Venice, Italy, May 2006, ACM Press, pp.266-269 more info, poster, eprint
	Ellis G P., Bertini E. and Dix A. The Sampling Lens : making sense of saturated visualisations. CHI 2005 Extended Abstract, Late Breaking Results: Posters, Portland, Oregon, USA, April 2005, ACM Press, pp.1351-54 abstract and references, poster, eprint
	Ellis G P and Dix A Visualising Web Visitations: a probabilistic approach. Proc. Information Visualisation 2004 (IV'04), London, July 2004, IEEE, pp.599-604 more info
	Ellis G P. and Dix A Quantum Web Fields And Molecular Meanderings: Visualising Web Visitations. Proc. International Working Conference on Advanced Visual Interfaces (AVI'04), Italy, May 2004, ACM Press, pp.197-200 outline and links, poster
	Ellis G P and Dix A Density control through random sampling : an architectural perspective. Proc. Information Visualisation 2002 (IV'02), London, July 2002, IEEE, pp.82-90 abstract and references
	Dix A and Ellis G P. by chance: enhancing interaction with large data sets through statistical sampling. Proc. International Working Conference on Advanced Visual Interfaces (AVI'02), L'Aquila, Italy, May 2002, ACM Press, pp.167-176 abstract, contents and references, eprint
	Pollitt A S, Ellis G P and Hosch I. Improving search quality using thesaurus for query specification and the presentation of search results.10 Years Anniversary Festschrift. ISKO - International Society for Knowledge Organization 1989-1999. Ed: Winfried Schmitz-Esser. Pub: ERGON-Verlag. November 1999
	Dix A and Ellis G P. Starting Simple - adding value to static visualisation through simple interaction. Proc. International Working Conference on Advanced Visual Interfaces (AVI'98), L'Aquila, Italy, May 25-27 1998, ACM Press, pp.124-134. See abstract and outline

	Group Project co-ordinator for CSc240 - Software Design & Project Skills [2004-2007]
	Assisting with HCI [2005/06]
	Assisting with CSc243 - Databases [2004/05]
	In a previous incarnation (at Huddersfield Univ), I ran courses on such topics as Information Visualisation, Computer Networks, Database Systems, Database Modeling, Program Design, Computer Systems Architecture

	Pollitt A S, Treglown M, Smith M P, Braekevelt P A J, Ellis G P, Finlay J E and Wade S J.Empowering Users for Improved Database Access and Analysis through the Application of Knowledge Structure Views, Progressive Refinement Techniques and a Design Approach Driven by Usability. Proc. Fourth International ISKO Conference 15-18 July 1996 Washington DC USA (Ed: R. Green) Advances in Knowledge Organisation Vol 5 (1996), Pub: Indeks Verlag, pp 231-241
	Pollitt A S, Ellis G P and Smith M B HIBROWSE for Bibliographic Databases. Information Science, Vol 20 No 6, December 1994, pp 413-426
	Pollitt A S, Smith M P and Ellis G P Peek-a-Boo revived - End-user searching of bibliographic databases using filteringviews. Online 94, 18th International Online Information Meeting, London, December 1994, pp 63-74
	Ellis G P and Lund G R. G2- A Design Language to help novice C programmers. 2nd All Ireland Conference on teaching of Computing, Dublin City University, Dublin, September 1994
	Pollitt A S, Smith M P and Ellis G P. Using the thesaurus to view and filter environmental databases: An example using EUROVOC to search EPOQUE - the European Parliament Online Query System. First European ISKO Conference on Environmental Knowledge Organisation and Information Management, Bratislava, Slovakia,14-16 September 1994
	Ellis G P, Finlay J E and Pollitt A S. HIBROWSE for Hotels: bridging the gap between users and system views of a database. Proc. 2nd International Workshop on User Interfaces to Database Systems, Lancaster, UK, Pub: Springer-Verlag Workshops in Computer Science, July 1994, pp 49-62
	Pollitt A S, Ellis G P and Hosch I. Improving search quality using thesauri for query specification and the presentation of search results. Proc. Third International ISKO Conference, Copenhagen, Denmark, June 1994 Advances in Knowledge Organisation Vol 4 (1994), pp 382-389
	4 publications prior to 1994