The Dynamap or the Dynamic Query Maptool is an interface designed to facilitate easier viewing and better analysis of map - related census data. The tool takes a shapefile as input and represents all the data in it in the form of adjustable widgets. Representation of the data in the form of widgets and allowing manipulation of more than one widget allows the formation of a composite query on the fly every time a widget is scrolled. Query previews form a novel visual approach for browsing large information warehouses. Query previews supply data distribution information about the database that is being searched and give continuous feedback about the size of the result set for the query as it is being formed.
Empirical results show that query previews improve user performance.
US Census Bureau maintains large amounts of tabular data. Browsing these tables poses similar problems that we aim to solve with the query preview approach. We believe query previews can improve access to Census data in terms of user performance and satisfaction. This demo shows the distribution of householders over three attributes, age, income level, and ethnic origin of the householder. Each attribute is represented by a bar chart.