<mods:mods version="3.0" xsi:schemaLocation="http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-0.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mods="http://www.loc.gov/mods/v3"><mods:titleInfo><mods:title>Answering Approximate Queries over Autonomous Web Databases</mods:title></mods:titleInfo><mods:name type="personal"><mods:namePart type="given">Xiangfu</mods:namePart><mods:namePart type="family">Meng</mods:namePart><mods:role><mods:roleTerm type="text">author</mods:roleTerm></mods:role></mods:name><mods:name type="personal"><mods:namePart type="given">Z. M.</mods:namePart><mods:namePart type="family">Ma</mods:namePart><mods:role><mods:roleTerm type="text">author</mods:roleTerm></mods:role></mods:name><mods:name type="personal"><mods:namePart type="given">Li</mods:namePart><mods:namePart type="family">Yan</mods:namePart><mods:role><mods:roleTerm type="text">author</mods:roleTerm></mods:role></mods:name><mods:abstract>To deal with the problem of empty or too little answers returned&#13;
from a Web database in response to a user query, this paper&#13;
proposes a novel approach to provide relevant and ranked query&#13;
results. Based on the user original query, we speculate how much&#13;
the user cares about each specified attribute and assign a&#13;
corresponding weight to it. This original query is then rewritten as&#13;
an approximate query by relaxing the query criteria range. The&#13;
relaxation order of all specified attributes and the relaxed degree&#13;
on each specified attribute are varied with the attribute weights.&#13;
For the approximate query results, we generate users’ contextual&#13;
preferences from database workload and use them to create a&#13;
priori orders of tuples in an off-line preprocessing step. Only a&#13;
few representative orders are saved, each corresponding to a set of&#13;
contexts. Then, these orders and associated contexts are used at&#13;
query time to expeditiously provide ranked answers. Results of a&#13;
preliminary user study demonstrate that our query relaxation and&#13;
results ranking methods can capture the user’s preferences&#13;
effectively. The efficiency and effectiveness of our approach is&#13;
also demonstrated by experimental result.&#13;
</mods:abstract><mods:originInfo><mods:dateIssued encoding="iso8061">2009-04</mods:dateIssued></mods:originInfo><mods:genre>Conference or Workshop Item</mods:genre></mods:mods>