| Author: | He, Zhian |
| Title: | Answering why-not questions on preference queries |
| Advisors: | Lo, Eric (COMP) |
| Degree: | Ph.D. |
| Year: | 2015 |
| Subject: | Expert systems (Computer science) Uncertainty (Information theory) Hong Kong Polytechnic University -- Dissertations |
| Department: | Department of Computing |
| Pages: | xviii, 135 pages : illustrations ; 30 cm |
| Language: | English |
| Abstract: | After decades of effort working on database performance, the quality and the usability of database systems have received more attention in recent years.Among all the studies that focus on improving databases' usability, the feature of explaining missing tuples in a query result, or the so-called "why-not" questions, has recently become an active topic. When using database system, users may sometimes feel frustrated if they find their expected tuples are not in the query results; and intuitively, they will ask "why are my expected tuples not in the results?" If a database system can give a good explanation for it, it would be very useful for users to understand and refine their queries.In this dissertation, we study the problem of answering why-not questions on preference queries. Our motivation is that we know many users love to pose this kinds of queries when they are making multi-criteria decisions. However, they would also want to know why if their expected answers do not show up in the query results. Therefore, we select three important kinds of preference queries (namely, top-k queries, top-k SQL queries and dominating queries) and develop algorithms to answer such "why-not" questions on each of them. |
| Rights: | All rights reserved |
| Access: | open access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b28163400.pdf | For All Users | 1.76 MB | Adobe PDF | View/Open |
Copyright Undertaking
As a bona fide Library user, I declare that:
- I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
- I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
- I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.
Please use this identifier to cite or link to this item:
https://theses.lib.polyu.edu.hk/handle/200/8080