TY  - JOUR
AB  - Purpose– The semantic and structural heterogeneity of large Extensible Markup Language (XML) digital libraries emphasizes the need of supporting approximate queries, i.e. queries where the matching conditions are relaxed so as to retrieve results that possibly partially satisfy the user's requests. The paper aims to propose a flexible query answering framework which efficiently supports complex approximate queries on XML data.Design/methodology/approach– To reduce the number of relaxations applicable to a query, the paper relies on the specification of user preferences about the types of approximations allowed. A specifically devised index structure which efficiently supports both semantic and structural approximations, according to the specified user preferences, is proposed. Also, a ranking model to quantify approximations in the results is presented.Findings– Personalized queries, on one hand, effectively narrow the space of query reformulations, on the other hand, enhance the user query capabilities with a great deal of flexibility and control over requests. As to the quality of results, the retrieval process considerably benefits because of the presence of user preferences in the queries. Experiments demonstrate the effectiveness and the efficiency of the proposal, as well as its scalability.Research limitations/implications– Future developments concern the evaluation of the effectiveness of personalization on queries through additional examinations of the effects of the variability of parameters expressing user preferences.Originality/value– The paper is intended for the research community and proposes a novel query model which incorporates user preferences about query relaxations on large heterogeneous XML data collections.
VL  - 4
IS  - 3
SN  - 1744-0084
DO  - 10.1108/17440080810901106
UR  - https://doi.org/10.1108/17440080810901106
AU  - Penzo Wilma
PY  - 2008
Y1  - 2008/01/01
TI  - Efficiently answering personalized queries on XML data
T2  - International Journal of Web Information Systems
PB  - Emerald Group Publishing Limited
SP  - 323
EP  - 351
Y2  - 2024/04/24
ER  -