TY - CONF T1 - Query previews in networked information systems T2 - Research and Technology Advances in Digital Libraries, 1996. ADL '96., Proceedings of the Third Forum on Y1 - 1996 A1 - Donn,K. A1 - Plaisant, Catherine A1 - Shneiderman, Ben KW - attribute KW - complexity;data KW - data KW - Earth KW - environment;networked KW - EOS-DIS;NASA KW - formulation;querying KW - formulation;user KW - hit KW - information KW - interfaces; KW - interfaces;exploratory KW - method;matching KW - networks;information KW - Observing KW - patterns;data KW - performance;networked KW - Preview;Query KW - process;rough KW - queries;computer KW - query KW - refinement;data KW - retrieval;information KW - services;interactive KW - sets;network KW - System-Data KW - System;Query KW - systems;query KW - user KW - values;zero KW - volume;dynamic AB - In a networked information system (such as the NASA Earth Observing System-Data Information System (EOS-DIS)), there are three major obstacles facing users in a querying process: network performance, data volume and data complexity. In order to overcome these obstacles, we propose a two phase approach to query formulation. The two phases are the Query Preview and the Query Refinement. In the Query Preview phase, users formulate an initial query by selecting rough attribute values. The estimated number of matching data sets is shown, graphically on preview bars which allows users to rapidly focus on a manageable number of relevant data sets. Query previews also prevent wasted steps by eliminating zero hit queries. When the estimated number of data sets is long enough, the initial query is submitted to the network which returns the metadata of the data sets for further refinement in the Query Refinement phase. The two phase approach to query formulation overcomes slow network performance, and reduces the data volume and data complexity, problems. This approach is especially appropriate for users who do not have extensive knowledge about the data and who prefer an exploratory method to discover data patterns and exceptions. Using this approach, we have developed dynamic query user interfaces to allow users to formulate their queries across a networked environment JA - Research and Technology Advances in Digital Libraries, 1996. ADL '96., Proceedings of the Third Forum on M3 - 10.1109/ADL.1996.502522 ER -