21,616 research outputs found
What Users See – Structures in Search Engine Results Pages
This paper investigates the composition of search engine results pages. We define what elements the most
popular web search engines use on their results pages (e.g., organic results, advertisements, shortcuts) and to
which degree they are used for popular vs. rare queries. Therefore, we send 500 queries of both types to the
major search engines Google, Yahoo, Live.com and Ask. We count how often the different elements are used by
the individual engines. In total, our study is based on 42,758 elements. Findings include that search engines use
quite different approaches to results pages composition and therefore, the user gets to see quite different results
sets depending on the search engine and search query used. Organic results still play the major role in the results
pages, but different shortcuts are of some importance, too. Regarding the frequency of certain host within the
results sets, we find that all search engines show Wikipedia results quite often, while other hosts shown depend
on the search engine used. Both Google and Yahoo prefer results from their own offerings (such as YouTube or
Yahoo Answers). Since we used the .com interfaces of the search engines, results may not be valid for other
country-specific interfaces
Digital Image Access & Retrieval
The 33th Annual Clinic on Library Applications of Data Processing, held at the University of Illinois at Urbana-Champaign in March of 1996, addressed the theme of "Digital Image Access & Retrieval." The papers from this conference cover a wide range of topics concerning digital imaging technology for visual resource collections. Papers covered three general areas: (1) systems, planning, and implementation; (2) automatic and semi-automatic indexing; and (3) preservation with the bulk of the conference focusing on indexing and retrieval.published or submitted for publicatio
How reliable are systematic reviews in empirical software engineering?
BACKGROUND – the systematic review is becoming a more commonly employed research instrument in
empirical software engineering. Before undue reliance is placed on the outcomes of such reviews it would seem useful to consider the robustness of the approach in this particular research context.
OBJECTIVE – the aim of this study is to assess the reliability of systematic reviews as a research instrument. In particular we wish to investigate the consistency of process and the stability of outcomes.
METHOD – we compare the results of two independent reviews under taken with a common research question.
RESULTS – the two reviews find similar answers to the research question, although the means of arriving at those answers vary.
CONCLUSIONS – in addressing a well-bounded research question, groups of researchers with similar domain experience can arrive at the same review outcomes, even though they may do so in different ways.
This provides evidence that, in this context at least, the systematic review is a robust research method
High-Performance Reachability Query Processing under Index Size Restrictions
In this paper, we propose a scalable and highly efficient index structure for
the reachability problem over graphs. We build on the well-known node interval
labeling scheme where the set of vertices reachable from a particular node is
compactly encoded as a collection of node identifier ranges. We impose an
explicit bound on the size of the index and flexibly assign approximate
reachability ranges to nodes of the graph such that the number of index probes
to answer a query is minimized. The resulting tunable index structure generates
a better range labeling if the space budget is increased, thus providing a
direct control over the trade off between index size and the query processing
performance. By using a fast recursive querying method in conjunction with our
index structure, we show that in practice, reachability queries can be answered
in the order of microseconds on an off-the-shelf computer - even for the case
of massive-scale real world graphs. Our claims are supported by an extensive
set of experimental results using a multitude of benchmark and real-world
web-scale graph datasets.Comment: 30 page
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