Marijn Koolen

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Marijn Koolen is an author.

Publications

Only those publications related to wikis are shown here.
Title Keyword(s) Published in Language DateThis property is a special property in this wiki. Abstract R C
Focus and element length for book and Wikipedia retrieval Lecture Notes in Computer Science English 2011 In this paper we describe our participation in INEX 2010 in the Ad Hoc Track and the Book Track. In the Ad Hoc track we investigate the impact of propagated anchor-text on article level precision and the impact of an element length prior on the within-document precision and recall. Using the article ranking of an document level run for both document and focused retrieval techniques, we find that focused retrieval techniques clearly outperform document retrieval, especially for the Focused and Restricted Relevant in Context Tasks, which limit the amount of text than can be returned per topic and per article respectively. Somewhat surprisingly, an element length prior increases within-document precision even when we restrict the amount of retrieved text to only 1000 characters per topic. The query-independent evidence of the length prior can help locate elements with a large fraction of relevant text. For the Book Track we look at the relative impact of retrieval units based on whole books, individual pages and multiple pages. 0 0
Focus and element length for book and wikipedia retrieval INEX English 2011 0 0
Focused search in books and Wikipedia: categories, links and relevance feedback INEX English 2010 0 0
Using anchor text, spam filtering and wikipedia for web search and entity ranking NIST Special Publication English 2010 In this paper, we document our efforts in participating to the TREC 2010 Entity Ranking and Web Tracks. We had multiple aims: For the Web Track we wanted to compare the effectiveness of anchor text of the category A and B collections and the impact of global document quality measures such as PageRank and spam scores. We find that documents in ClueWeb09 category B have a higher probability of being retrieved than other documents in category A. In ClueWeb09 category B, spam is mainly an issue for full-text retrieval. Anchor text suffers little from spam. Spam scores can be used to filter spam but also to find key resources. Documents that are least likely to be spam tend to be high-quality results. For the Entity Ranking Track, we use Wikipedia as a pivot to find relevant entities on the Web. Using category information to retrieve entities within Wikipedia leads to large improvements. Although we achieve large improvements over our baseline run that does not use category information, our best scores are still weak. Following the external links onWikipedia pages to find the homepages of the entities in the ClueWeb collection, works better than searching an anchor text index, and combining the external links with searching an anchor text index. 0 0
Comparative analysis of clicks and judgments ir evaluation Transaction log analysis
Information retrieval
Wikipedia
Proceedings of Workshop on Web Search Click Data, WSCD'09 English 2009 Queries and click-through data taken from search engine transaction logs is an attractive alternative to traditional test collections, due to its volume and the direct relation to end-user querying. The overall aim of this paper is to answer the question: How does click-through data differ from explicit human relevance judgments in information retrieval evaluation? We compare a traditional test collection with manual judgments to transaction log based test collections- by using queries as topics and subsequent clicks as pseudorelevance judgments for the clicked results. Specifically, we investigate the following two research questions: Firstly, are there significant differences between clicks and relevance judgments. Earlier research suggests that although clicks and explicit judgments show reasonable agreement, clicks are different from static absolute relevance judgments. Secondly, are there significant differences between system ranking based on clicks and based on relevance judgments? This is an open uestion, but earlier research suggests that comparative evaluation in terms of system ranking is remarkably robust. Copyright 2009 ACM. 0 0
Is Wikipedia link structure different? Wikipedia
Link evidence
Information retrieval
WSDM English 2009 0 1
Overview of the INEX 2008 Ad hoc track Lecture Notes in Computer Science English 2009 This paper gives an overview of the INEX 2008 Ad Hoc Track. The main goals of the Ad Hoc Track were two-fold. The first goal was to investigate the value of the internal document structure (as provided by the XML mark-up) for retrieving relevant information. This is a continuation of INEX 2007 and, for this reason, the retrieval results are liberalized to arbitrary passages and measures were chosen to fairly compare systems retrieving elements, ranges of elements, and arbitrary passages. The second goal was to compare focused retrieval to article retrieval more directly than in earlier years. For this reason, standard document retrieval rankings have been derived from all runs, and evaluated with standard measures. In addition, a set of queries targeting Wikipedia have been derived from a proxy log, and the runs are also evaluated against the clicked Wikipedia pages. The INEX 2008 Ad Hoc Track featured three tasks: For the Focused Task a ranked-list of non-overlapping results (elements or passages) was needed. For the Relevant in Context Task non-overlapping results (elements or passages) were returned grouped by the article from which they came. For the Best in Context Task a single starting point (element start tag or passage start) for each article was needed. We discuss the results for the three tasks, and examine the relative effectiveness of element and passage retrieval. This is examined in the context of content only (CO, or Keyword) search as well as content and structure (CAS, or structured) search. Finally, we look at the ability of focused retrieval techniques to rank articles, using standard document retrieval techniques, both against the judged topics as well as against queries and clicks from a proxy log. 0 0
Result diversity and entity ranking experiments: Anchors, links, text and Wikipedia NIST Special Publication English 2009 In this paper, we document our efforts in participating to the TREC 2009 Entity Ranking and Web Tracks. We had multiple aims: For the Web Track's Adhoc task we experiment with document text and anchor text representation, and the use of the link structure. For the Web Track's Diversity task we experiment with using a top down sliding window that, given the top ranked documents, chooses as the next ranked document the one that has the most unique terms or links. We test our sliding window method on a standard document text index and an index of propagated anchor texts. We also experiment with extreme query expansions by taking the top n results of the initial ranking as multi-faceted aspects of the topic to construct n relevance models to obtain n sets of results. A final diverse set of results is obtained by merging the n results lists. For the Entity Ranking Track, we also explore the effectiveness of the anchor text representation, look at the co-citation graph, and experiment with using Wikipedia as a pivot. Our main findings can be summarized as follows: Anchor text is very effective for diversity. It gives high early precision and the results cover more relevant sub-topics than the document text index. Our baseline runs have low diversity, which limits the possible impact of the sliding window approach. New link information seems more effective for diversifying text-based search results than the amount of unique terms added by a document. In the entity ranking task, anchor text finds few primary pages, but it does retrieve a large number of relevant pages. Using Wikipedia as a pivot results in large gains of P10 and NDCG when only primary pages are considered. Although the links between the Wikipedia entities and pages in the Clueweb collection are sparse, the precision of the existing links is very high. 0 0
The impact of document level ranking on focused retrieval Lecture Notes in Computer Science English 2009 Document retrieval techniques have proven to be competitive methods in the evaluation of focused retrieval. Although focused approaches such as XML element retrieval and passage retrieval allow for locating the relevant text within a document, using the larger context of the whole document often leads to superior document level ranking. In this paper we investigate the impact of using the document retrieval ranking in two collections used in the INEX 2008 Ad hoc and Book Tracks; the relatively short documents of the Wikipedia collection and the much longer books in the Book Track collection. We experiment with several methods of combining document and element retrieval approaches. Our findings are that 1) we can get the best of both worlds and improve upon both individual retrieval strategies by retaining the document ranking of the document retrieval approach and replacing the documents by the retrieved elements of the element retrieval approach, and 2) using document level ranking has a positive impact on focused retrieval in Wikipedia, but has more impact on the much longer books in the Book Track collection. 0 0
Using wikipedia categories for ad hoc search Ad hoc retrieval
Category information
Wikipedia
SIGIR English 2009 0 0
What's in a link? from document importance to topical relevance Lecture Notes in Computer Science English 2009 Web information retrieval is best known for its use of the Web's link structure as a source of evidence. Global link evidence is by nature query-independent, and is therefore no direct indicator of the topical relevance of a document for a given search request. As a result, link information is usually considered to be useful to identify the 'importance' of documents. Local link evidence, in contrast, is query-dependent and could in principle be related to the topical relevance. We analyse the link evidence in Wikipedia using a large set of ad hoc retrieval topics and relevance judgements to investigate the relation between link evidence and topical relevance. 0 0
Wikipedia pages as entry points for book search English 2009 A lot of the world's knowledge is stored in books, which, as a result of recent mass-digitisation efforts, are increasingly available online. Search engines, such as Google Books, provide mechanisms for searchers to enter this vast knowledge space using queries as entry points. In this paper, we view Wikipedia as a summary of this world knowledge and aim to use this resource to guide users to relevant books. Thus, we investigate possible ways of using Wikipedia as an intermediary between the user's query and a collection of books being searched. We experiment with traditional query expansion techniques, exploiting Wikipedia articles as rich sources of information that can augment the user's query. We then propose a novel approach based on link distance in an extended Wikipedia graph: we associate books with Wikipedia pages that cite these books and use the link distance between these nodes and the pages that match the user query as an estimation of a book's relevance to the query. Our results show that a) classical query expansion using terms extracted from query pages leads to increased precision, and b) link distance between query and book pages in Wikipedia provides a good indicator of relevance that can boost the retrieval score of relevant books in the result ranking of a book search engine. 0 0
The Importance of Link Evidence in Wikipedia English 2008 Wikipedia is one of the most popular information sources on the Web. The free encyclopedia is densely linked. The link structure in Wikipedia differs from the Web at large: internal links in Wikipedia are typically based on words naturally occurring in a page, and link to another semantically related entry. Our main aim is to find out if Wikipedia’s link structure can be exploited to improve ad hoc information retrieval. We first analyse the relation between Wikipedia links and the relevance of pages. We then experiment with use of link evidence in the focused retrieval of Wikipedia content, based on the test collection of INEX 2006. Our main findings are: First, our analysis of the link structure reveals that the Wikipedia link structure is a (possibly weak) indicator of relevance. Second, our experiments on INEX ad hoc retrieval tasks reveal that if the link evidence is made sensitive to the local context we see a significant improvement of retrieval effectiveness. Hence, in contrast with earlier TREC experiments using crawled Web data, we have shown that Wikipedia’s link structure can help improve the effectiveness of ad hoc retrieval. 0 0
The importance of link evidence in Wikipedia Lecture Notes in Computer Science English 2008 Wikipedia is one of the most popular information sources on the Web. The free encyclopedia is densely linked. The link structure in Wikipedia differs from the Web at large: internal links in Wikipedia are typically based on words naturally occurring in a page, and link to another semantically related entry. Our main aim is to find out if Wikipedia's link structure can be exploited to improve ad hoc information retrieval. We first analyse the relation between Wikipedia links and the relevance of pages. We then experiment with use of link evidence in the focused retrieval of Wikipedia content, based on the test collection of INEX 2006. Our main findings are: First, our analysis of the link structure reveals that the Wikipedia link structure is a (possibly weak) indicator of relevance. Second, our experiments on INEX ad hoc retrieval tasks reveal that if the link evidence is made sensitive to the local context we see a significant improvement of retrieval effectiveness. Hence, in contrast with earlier TREC experiments using crawled Web data, we have shown that Wikipedia's link structure can help improve the effectiveness of ad hoc retrieval. 0 0
Using and Detecting Links in Wikipedia English 2008 In this paper, we document our efforts at INEX 2007 where we participated in the Ad Hoc Track, the Link the Wiki Track, and the Interactive Track that continued from INEX 2006. Our main aims at INEX 2007 were the following. For the Ad Hoc Track, we investigated the effectiveness of incorporating link evidence into the model, and of a CAS filtering method exploiting the structural hints in the INEX topics. For the Link the Wiki Track, we investigated the relative effectiveness of link detection based on retrieving similar documents with the Vector Space Model, and then filter with the names of Wikipedia articles to establish a link. For the Interactive Track, we took part in the interactive experiment comparing an element retrieval system with a passage retrieval system. The main results are the following. For the Ad Hoc Track, we see that link priors improve most of our runs for the Relevant in Context and Best in Context Tasks, and that CAS pool filtering is effective for the Relevant in Context and Best in Context Tasks. For the Link the Wiki Track, the results show that detecting links with name matching works relatively well, though links were generally under-generated, which hurt the performance. For the Interactive Track, our test-persons showed a weak preference for the element retrieval system over the passage retrieval system. 0 0
Using and detecting links in Wikipedia Lecture Notes in Computer Science English 2008 In this paper, we document our efforts at INEX 2007 where we participated in the Ad Hoc Track, the Link the Wiki Track, and the Interactive Track that continued from INEX 2006. Our main aims at INEX 2007 were the following. For the Ad Hoc Track, we investigated the effectiveness of incorporating link evidence into the model, and of a CAS filtering method exploiting the structural hints in the INEX topics. For the Link the Wiki Track, we investigated the relative effectiveness of link detection based on retrieving similar documents with the Vector Space Model, and then filter with the names of Wikipedia articles to establish a link. For the Interactive Track, we took part in the interactive experiment comparing an element retrieval system with a passage retrieval system. The main results are the following. For the Ad Hoc Track, we see that link priors improve most of our runs for the Relevant in Context and Best in Context Tasks, and that CAS pool filtering is effective for the Relevant in Context and Best in Context Tasks. For the Link the Wiki Track, the results show that detecting links with name matching works relatively well, though links were generally under-generated, which hurt the performance. For the Interactive Track, our test-persons showed a weak preference for the element retrieval system over the passage retrieval system. 0 0