Inspired by empirical studies of networked systems such as the Internet, social networks, and biological networks, researchers have in recent years developed a variety of techniques and models to help us understand or predict the behavior of these systems. Here we review developments in this field, including such concepts as the small-world effect, degree distributions, clustering, network correlations, random graph models, models of network growth and preferential attachment, and dynamical processes taking place on networks.

/pdf/the-structure-and-function-of-complex-networks-34deompc9l.pdf

The Structure and Function of Complex Networks

Statistical approaches to processing natural language text have become dominant in recent years This foundational text is the first comprehensive introduction to statistical natural language processing (NLP) to appear The book contains all the theory and algorithms needed for building NLP tools It provides broad but rigorous coverage of mathematical and linguistic foundations, as well as detailed discussion of statistical methods, allowing students and researchers to construct their own implementations The book covers collocation finding, word sense disambiguation, probabilistic parsing, information retrieval, and other applications

/pdf/foundations-of-statistical-natural-language-processing-1ou5e6c2q6.pdf

Foundations of Statistical Natural Language Processing

The network structure of a hyperlinked environment can be a rich source of information about the content of the environment, provided we have effective means for understanding it. We develop a set of algorithmic tools for extracting information from the link structures of such environments, and report on experiments that demonstrate their effectiveness in a variety of context on the World Wide Web. The central issue we address within our framework is the distillation of broad search topics, through the discovery of “authorative” information sources on such topics. We propose and test an algorithmic formulation of the notion of authority, based on the relationship between a set of relevant authoritative pages and the set of “hub pages” that join them together in the link structure. Our formulation has connections to the eigenvectors of certain matrices associated with the link graph; these connections in turn motivate additional heuristrics for link-based analysis.

/pdf/authoritative-sources-in-a-hyperlinked-environment-1p23r698i9.pdf

Authoritative sources in a hyperlinked environment

The structure of scientific collaboration networks is investigated. Two scientists are considered connected if they have authored a paper together and explicit networks of such connections are constructed by using data drawn from a number of databases, including MEDLINE (biomedical research), the Los Alamos e-Print Archive (physics), and NCSTRL (computer science). I show that these collaboration networks form “small worlds,” in which randomly chosen pairs of scientists are typically separated by only a short path of intermediate acquaintances. I further give results for mean and distribution of numbers of collaborators of authors, demonstrate the presence of clustering in the networks, and highlight a number of apparent differences in the patterns of collaboration between the fields studied.

/pdf/the-structure-of-scientific-collaboration-networks-24jlzt2hdf.pdf

The structure of scientific collaboration networks

Using computer databases of scientific papers in physics, biomedical research, and computer science, we have constructed networks of collaboration between scientists in each of these disciplines. In these networks two scientists are considered connected if they have coauthored one or more papers together. Here we study a variety of nonlocal statistics for these networks, such as typical distances between scientists through the network, and measures of centrality such as closeness and betweenness. We further argue that simple networks such as these cannot capture variation in the strength of collaborative ties and propose a measure of collaboration strength based on the number of papers coauthored by pairs of scientists, and the number of other scientists with whom they coauthored those papers.

https://arxiv.org/pdf/cond-mat/0011144.pdf

Scientific collaboration networks. II. Shortest paths, weighted networks, and centrality

The scope and significance of the field of informetrics is defined and related to the earlier fields of bibliometrics and scientometrics. The phenomena studied by informetricians are identified. The major contributors to the field in the past are described and current emphases are related to the contributions in this Special Issue.

An introduction to informetrics

The decisions that must be made by an investigator in carrying out an information retrieval experiment are described. Guidance is provided on a number of issues, specifically determining the need for testing, choosing the type of test (laboratory or operational), defining the variables, developing or using databases, finding queries, processing queries, assigning treatments to experimental units, collecting the data, analyzing the data, and presenting the results.

The pragmatics of information retrieval experimentation, revisited

A statistical analysis of the TREC-3 data shows that performance differences across queries is greater than performance differences across participants runs. Generally, groups of runs which do not differ significantly at lerge, sometimes accounting for over half the runs. Correlation among the various performance measures is high.

A Statistical Analysis of the TREC-3 Data

As an introduction to the papers in this special issue, some of the major problems facing investigators evaluating information retrieval systems are presented. These problems include the question of the necessity of using real users, as opposed to subject experts, in making relevance judgements, the possibility of evaluating individual components of the retrieval process, rather than the process as a whole, the kinds of aggregation that are appropriate for the measures used in evaluating information retrieval systems, the value of an analytic or simulatory, as opposed to an experimental, approach in evaluating retrieval systems, the difficulties in evaluating interactive systems, and the kinds of generalization which are possible from information retrieval tests. © 1996 John Wiley & Sons, Inc.

Some perspectives on the evaluation of information retrieval systems

This article examines the classification of link types within hypertext databases. Do labeled links act as cues, enabling understanding of the structure and leading to more informed navigational choices? Although there is anecdotal evidence that indicating link types to readers is useful in hypertext systems, there is little experimental data to support this position. This study tries to provide an experimental basis for the development of labels identifying link types. It addresses whether labeling the different types of links affects hypertext searching by providing or enhancing a structure for readers of nonlinear texts. An experiment was run to determine which of the following three conditions serve users with better cues and lead to increased performance in both browsing and querying scenarios: 1) Providing only organizational links; 2) Adding unlabeled semantic, rhetorical, and pragmatic links in addition to the organizational links; and 3) Adding labeled semantic, rhetorical, and pragmatic links to the organizational links. The experiment used a between subjects design where subjects were library science students. SuperBook was used as the hypertext platform and the OCLC Cataloguing Users' Guide was used as the hypertext document. The statistical results indicate that there was no significant difference between the three conditions in the browsing task. However, subjects who had labeled content-based links performed significantly better on the querying task.

Jean Tague-Sutcliffe

Papers

An introduction to informetrics

The pragmatics of information retrieval experimentation, revisited

A Statistical Analysis of the TREC-3 Data

Some perspectives on the evaluation of information retrieval systems

Labeled, typed links as cues when reading hypertext documents