Designing Visual Attention and User Interaction for a Geoportal using SVG

For the SVG Open 2005 conference

Keywords: visual attention, interaction, geoportal

Trias Aditya
International Institute for Geo-Information Science & Earth Observation (ITC)
Hengelosestraat 99
Enschede
7514 AE
The Netherlands
aditya@itc.nl

Biography

Trias Aditya is a PhD student at International Institute for Geo-Information Science & Earth Observation (ITC), The Netherlands and Lecturer at the Department of Geodetic Engineering, UGM, Indonesia.

Drs. Barrend Köbben
International Institute for Geo-Information Science & Earth Observation (ITC)
Hengelosestraat 99
Enschede
7514 AE
The Netherlands
kobben@itc.nl

Biography

Barend Köbben is a Senior Lecturer at the Department of Geo-Information Proccessing, International Institute for Geo-Information Science & Earth Observation (ITC), The Netherlands

Prof. Dr. Menno-Jan Kraak
International Institute for Geo-Information Science & Earth Observation (ITC)
Hengelosestraat 99
Enschede
7514 AE
The Netherlands
kraak@itc.nl

Biography

Menno-jan Kraak is a Professor in Geovisualization, Chairman of the Department of Geo-Information Processing, International Institute for Geo-Information Science & Earth Observation (ITC), The Netherlands


Table of Contents


1. Introduction
2. A brief description of the framework
3. Search Interfaces
4. Discussion
Bibliography

1. Introduction

The task of determining which data and information is relevant has become more difficult for internet-users. Providing search interfaces enabling users to “search in the context” in order to get the “relevant feedback” has been indicated as one of the most important research issues. The major rationale for the existence of geoportals and geo digital libraries is to provide access mechanisms to various geo data and information. In this context, unfortunately supports to assist perceptual and cognitive limits of the users are still lacking. This work investigates the prospects of using SVG technology to offer a usable visualization of and user interactions to the geoportal.

This study is about the use and the development of web atlas as an alternative for accessing geodata in the (geo)spatial data infrastructure (SDI) framework. Use of the atlas as metaphor is motivated by the familiarity and functionality that the atlas offers. Regarding familiarity, from the map use perspective, maps have been seen as an effective medium to study characteristics and relations of some part of real world phenomena. Further, atlases have been used as a tool to solve their inquiries about various topics of geographic phenomena, such as geographic names, population, economic development, and politics for a certain place. Regarding functionality, maps and particularly atlases have the capabilities to allow readers/users explaining patterns, comparing items (Kraak and Ormeling 2002 p.201-204). In this way an atlas interface can help the user to answer their questions not only regarding what data are available but also which data and why these data and information are useful for their application.

2. A brief description of the framework

The work utilizes data-driven web application using the model-view-control paradigm. In this regard, the model corresponds to metadata summaries of available geospatial data (encoded in RDF/XML format), map layers (stored as MySQL databases conforming to OGC Simple Features) (Köbben 2004), and supporting multimedia (e.g. images, animations, text descriptions). The view component comprises of navigation interfaces, search interfaces, and map-legend interfaces. XSLT, Servlet, and JSP technologies are used in the control component. They are dealing with data transformation, mapping data and search results, and managing functionalities offered to enable user interactions. This paper will only focus on the view component of the study with the use of SVG.

3. Search Interfaces

3.1. Visualization

Regarding the visualization scheme, this will present strategies to provide usable graphic symbols applying visual search guidelines on top of search and map interfaces. These symbols are used to assist users’ pre-attentive processing in performing a task of searching for geospatial data.

The research questions this paper deals with are: How to present search results on top of map and search interfaces in the form of SVG as a systematic pre-attentive representation referring to rules (e.g. Gestals laws for similarity, closure, proximity) and criteria designed (e.g. the level of detail of representation regarding zoom functionality)? In this context, we investigate the applicability of (external) CSS to implement these rules and design criteria. In addition, some functionalities in the control component (as methods in a Servlet) aimed to enhance these CSS implementations are required.

3.2. Interaction

Regarding user interactions, this will elaborate how SVG user interfaces should be built to enrich functionalities facilitating tasks for defining questions and reviewing the search results. We aim to provide usable interactions through mouse pointer actions: hover and click. These can be useful to provide possibilities to enable multi-linked views, sorting of search results, and anchoring selected items. These possibilities are difficult to be found in the current geoportals, whereas such actions will help users to facilitate users tasks in discovering geodata.In this context, we are interested to delve into the DOM utilization to enable users interaction (topics of linking, interactivity, and event-scripting in the SVG 1.1. specification (W3C, 2003) and its newest draft).

4. Discussion

Within this research framework, a next step to enhance the prototype towards a scalable geoportal includes proposing more user interactions to strengthen comparison means (with visual dynamic queries). Secondly, in order to improve the usability of the SVG interfaces, the users’ experiences in searching data and interacting with geoportal are required to be observed through a usability testing. Through this testing, the limitations and problems existing in the current SVG interfaces can be revealed and refined.

Bibliography

[RIMapper]
LBS & Telecartography Proceeding Köbben, B. "RIMapper - A Test Bed for Online Risk Indicator Maps Using Data-Driven SVG Visualization." Location Based Services and TeleCartography, Vienna.
[Carto&Vis]
Cartography Vis. of Spatial Data Kraak, M.-J., and Ormeling, F. J. (2002). Cartography Visualization of Spatial Data, Addison Wesley Longman, London.
[SVG1.1.]
W3C reccomendation W3C(2003). Scalable Vector Graphics (SVG) 1.1 Specification at http://www.w3.org/TR/SVG/index.html#minitoc

XHTML rendition made possible by SchemaSoft's Document Interpreter™ technology.