Complete answer aggregates for treelike databases

Meuss, Holger; Schulz, Klaus U.

doi:10.1145/382979.383042

Cited by 15 publications

(21 citation statements)

References 34 publications

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“…X 2 has been conceived, implemented and tested at the University of Munich over the last five years. While in the beginning we concentrated on algorithmic problems related to query evaluation [15], the focus of our recent work is the second of the aforementioned challenges. After a series of practical tests, a third general objective has been added: In order to formulate a query with interesting structural conditions, the user must have an idea of the structure of documents in the repository.…”

Section: Send Offprint Requests To: Holger Meussmentioning

confidence: 99%

“…The full answer space for the query is computed and represented in the form of a so-called Complete Answer Aggregate (CAA) [15]. The CAA collects all nodes (elements) of the database that contribute to some answer, avoiding redundancies.…”

Section: System Overviewmentioning

confidence: 99%

“…In X 2 , by contrast, the full set of answers is computed and visually represented in the form of a Complete Answer Aggregate (CAA). This data structure is introduced informally here, a formal definition can be found in [15]. CAAs collect answers in a structured, condensed and non-redundant way, using mechanisms for structure sharing.…”

Section: Complete Answer Aggregatesmentioning

confidence: 99%

“…The algorithm for computing the CAA (described in [15]) for a query Q runs in time O(|Q| · |D| · h D · log(|D|)) where |Q| and |D| respectively denote the size of the query and the database, and h D denotes the maximal depth of a path in a document. If no ordering constraints are used, then the complexity is O(|Q| · |D| · h D ), which is optimal [15].…”

Section: Complete Answer Aggregatesmentioning

confidence: 99%

“…If no ordering constraints are used, then the complexity is O(|Q| · |D| · h D ), which is optimal [15]. We developed a special index structure for textual XML documents, the CADG [25].…”

Section: Complete Answer Aggregatesmentioning

confidence: 99%

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Visual exploration and retrieval of XML document collections with the generic system X2

Meuss

Schulz²,

Weigel³

et al. 2005

Int J Digit Libr

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Abstract. This article reports on the XML retrieval system X 2 which has been developed at the University of Munich over the last five years. In a typical session with X 2 , the user first browses a structural summary of the XML database in order to select interesting elements and keywords occurring in documents. Using this intermediate result, queries combining structure and textual references are composed semiautomatically. After query evaluation, the full set of answers is presented in a visual and structured way. X 2 largely exploits the structure found in documents, queries and answers to enable new interactive visualization and exploration techniques that support mixed IR and database-oriented querying, thus bridging the gap between these three views on the data to be retrieved. Another salient characteristic of X 2 which distinguishes it from other visual query systems for XML is that it supports various degrees of detailedness in the presentation of answers, as well as techniques for dynamically reordering and grouping retrieved elements once the complete answer set has been computed.

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Section: Send Offprint Requests To: Holger Meussmentioning

confidence: 99%

Section: System Overviewmentioning

confidence: 99%

Section: Complete Answer Aggregatesmentioning

confidence: 99%

Section: Complete Answer Aggregatesmentioning

confidence: 99%

“…If no ordering constraints are used, then the complexity is O(|Q| · |D| · h D ), which is optimal [15]. We developed a special index structure for textual XML documents, the CADG [25].…”

Section: Complete Answer Aggregatesmentioning

confidence: 99%

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Visual exploration and retrieval of XML document collections with the generic system X2

Meuss

Schulz²,

Weigel³

et al. 2005

Int J Digit Libr

Self Cite

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XQL and proximal nodes

Baeza-Yates¹,

Navarro²

2002

J. Am. Soc. Inf. Sci.

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Despite the fact that several models to structure text documents and to query on this structure have been proposed in the past, a standard has emerged only relatively recently with the introduction of XML and its proposed query language XQL, on which we focus in this article. Although there exist some implementations of XQL, efficiency of the query engine is still a problem. We show in this article that an already existing model, Proximal Nodes, which was defined with the goal of efficiency in mind, can be used as an efficient query engine behind an XQL front-end.

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Global vs. localized search: A comparison of database selection methods in a hierarchical environment

Conrad

Claussen²,

Yang

2002

Proc of Assoc for Info

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In this work, we compare standard global IR searching with more localized techniques to address the database selection problem. We conduct a series of experiments to compare the retrieval effectiveness of three separate search modes using a hierarchically structured data environment of textual database representations. The data environment is represented as a tree-like structure containing over 15,000 unique databases and approximately 100,000 total leaf nodes. The search modes consist of varying degrees of browse and search, from a global search at the root node to a refined search at a sub-node using dynamically-calculated inverse document frequencies (idfs) to score the candidate databases for probable relevance. Our findings indicate that a browse plus search approach that relies upon localized searching from sub-nodes in this environment produces the most effective results. IntroductionThe continued growth of online databases has made the work of finding the most relevant databases increasingly challenging. Until recently, the ability to search a metadata repository as well as 'drill down' into its hierarchical structure, e.g., as in a data directory, have largely remained separate activities. That is, browse and search tasks in the same repository have often been presented as mutually exclusive. As a result, large numbers of users exit online systems with unmet information needs when failing to find relevant sources of interest. This was the case with the Westlaw (Database) Directory. We hypothesized that if users could first browse to a potentially relevant subdirectory in the large directory, results from a search in the sub-directory would be more precise than results from a search on the entire directory. To test the effectiveness of browse plus search functionality, we designed and conducted a series of experiments on three search-modes, using the same set of real user queries. These search-modes include (1) a global search of the directory from the root node, (2) a localized search of the relevant sub-directories using global idfs,' and (3) a localized search of the relevant sub-directories using the appropriate local idfs. In the next section we review related work. Section 3 briefly describes our operational environment while section 4 discusses the underlying data. Section 5 describes the user queries harnessed for this investigation. Section 6 addresses the particular t r i d f scoring algorithm used. Our experiments are outlined in section 7 and our results are presented in section 8. In section 9 we draw our conclusions and in section 10 we mention future applications of this browse and search technology. Previous WorkAn appreciable body of work has focused on searching distributed databases of textual documents for relevant information in response to user queries (Gravano 1994; Callan, 1995;Yuwono, 1997;French 1999). Yet such fully automated retrieval and the corpus of related research which followed have been performed independent of additional user involvement. For this reason, the IR commu...

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Complete answer aggregates for treelike databases

Cited by 15 publications

References 34 publications

Visual exploration and retrieval of XML document collections with the generic system X2

Visual exploration and retrieval of XML document collections with the generic system X2

XQL and proximal nodes

Global vs. localized search: A comparison of database selection methods in a hierarchical environment

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