A New SIG on Database Visualization

The SIG are (so far):

Steve Benford, John Boyle, Richard Cooper, Jessie Kennedy, John Mariani, Tom Rodden.

Introduction

A group of independent researchers in the field of database visualization have come together to collaborate and exchange ideas. The group is mainly interested in the use of 3D animated graphics to aid users when interacting with database management systems. A number of systems have been developed which use 3D graphical user interfaces for database access. It is felt that three dimensional graphics can offer usability and expressive power for database interfaces, which is lacking in 2D interfaces.

Background

Database technology has made it possible to model and store real world data in a comprehensive manner. This data can then be manipulated, updated, or queried by a user. However most such manipulations have to be done through a rigid and unforgiving syntactical language such as SQL. It is hardly surprising that work on designing user interfaces to databases has been going on for over 20 years - but still the interfaces for database management systems do not offer the user the power to interact with the actual data in an easy manner. This is mainly due to the limitations of the 'desktop metaphor' - when attempting to deal with such abstractions as constructing queries and visualizing results a more powerful expressive system is needed. Interfaces to databases usually come in one of two forms: database schema or table based. A schema is an abstract representation of the real world data. This schema can be used by the designer as the basis of the interface (GUIDE). An alternative metaphor when constructing interfaces to databases is to use a diagrammatic picture of a relation table - where the user fills in columns to define the query - this approach was first suggests by M Zloof (QBE) in 1974 and is still used today in a number of popular systems (Dbase (Borland), Paradox (Borland) and Access (Microsoft)).

Both of these types of interface lack any powerful visual techniques to guide the user when examining the results or forming the query.

Present research by the SIG

Three dimensional graphics can be used to visualize the whole process of querying, data examination and data retrieval from a database. A number of independent research groups inside the United Kingdom have all found limitations with using flat two dimensional displays, and so have begun experimenting with 3D interactive animated visualizations. These visualizations are designed to aid the user in the querying process.

Three different systems have been built:

Amaze
J Boyle and P Gray (Aberdeen) A 3D graphical user interface to a database management system. The user constructs a query by attaching constraint objects to a schema in a 3D environment. The results from the query are portrayed to the user in another 3D window, the quantity and interrelationships between the results is visualized.
PITS
S Benford (Nottingham) S Mariani and T Rodden (Lancaster) Populated Information Terrains (PITS) combines ideas from the fields of Computer Supported Cooperative Work (CSCW), Virtual Reality and databases to create multi-actor virtual environments which support visualization of, and cooperative work within, shared data. Attributes of the data are also visualized by a number of techniques (size, shape, animation).
Winona
M Rapley and J Kennedy (Napier) A PC based 3D interface to a database has been built. This encompasses the schema visualization and result representation into one 3D object.

Each of these systems builds upon the same idea, and that is of being able to visualize the database in some abstract manner. They attempt to give the user more than just a means of querying the database, they provide the user a visual reference through which they can enter into a dialogue with the database.

Future Directions

Future work is planned in both a collaborative and individual manner. Most of the work to date has been in testing the feasibility of using 3D graphics as an effective medium in helping the user describe the query they wish to perform, and to allow the user to browse through a visualization of results.

The next stage involves four avenues of enquiry:

Evaluation
This work is just reaching the end of its prototype stage, and functional systems have been developed. The next stage is to attempt to assess the usability /desirability of the different visualizations that have been suggested. One of the research groups has dedicated itself to producing evaluation methods.
Improved visualizations
The visualizations techniques that have been used are relatively simple. The groups are looking at different aspects of database visualization, and more complex visualizations are being planned.
Virtual Interfaces
While two of the interfaces (Amaze and Winona) use an object-centric approach for their interaction, PITS has been placed inside a virtual environment (DIVE). A number of issues are raised with such an environment, most importantly how to carry out social interaction. The feasibility of placing another of the interfaces (Amaze) into the DIVE virtual environment is being explored.
Different types of data
The interfaces developed so far are only to scalar data. There are plans to build an interface to the complex underlying software store in a persistent programming language, and to develop/explore techiques for querying image data.

Conclusion

The SIG is interested in visualizing database and the operations the user wishes to perform on it. So far the group has addressed visualization of:

The database information - visualizing the underlying conceptual schema and visualizing the quantity of data in the database.
The query - allowing the user to graphically construct a query, visualizing updates and changes through animation.
The results the user has obtained from their query - showing how the results are interrelated, visualizing n-dimensional results and visualizing attributes of the results.

The strength of the group is that while all the researchers worked independently, they all concluded that when interacting with a database, a visual approach was needed. They have now come together with a common goal in mind: to build a new generation of user interfaces that will take database access out of the hands of the select few and place it in the hands of the non-specialist user.

John Boyle
john@csd.abdn.ac.uk