Unraveling the dynamics of growth, aging and inflation for citations to scientific articles from specific research fields

We analyze the time evolution of citations acquired by articles from journals of the American Physical Society (PRA, PRB, PRC, PRD, PRE and PRL). The observed change over time in the number of papers published in each journal is considered an exogenously caused variation in citability that is accounted for by a normalization. The appropriately inflation-adjusted citation rates are found to be separable into a preferential-attachment-type growth kernel and a purely obsolescence-related (i.e., monotonously decreasing as a function of time since publication) aging function. Variations in the empirically extracted parameters of the growth kernels and aging functions associated with different journals point to research-field-specific characteristics of citation intensity and knowledge flow. Comparison with analogous results for the citation dynamics of technology-disaggregated cohorts of patents provides deeper insight into the basic principles of information propagation as indicated by citing behavior.Comment: 13 pages, 6 figures, Elsevier style, v2: revised version to appear in J. Informetric

In Search of Convergence: A Co-citation Analysis of Three Sport Management Journals

Responding to a series of articles in sport management literature calling for more diversity in terms of areas of interest or methods, this study warns against the danger of excessively fragmenting this field of research. The works of Kuhn (1962) and Pfeffer (1993) are taken as the basis of an argument that connects convergence with scientific strength. However, being aware of the large number of counterarguments directed at this line of reasoning, a new model of convergence, which focuses on clusters of research contributions with similar areas of interest, methods, and concepts, is proposed. The existence of these clusters is determined with the help of a bibliometric analysis of publications in three sport management journals. This examination determines that there are justified reasons to be concerned about the level of convergence in the field, pointing out to a reduced ability to create large clusters of contributions in similar areas of interest

Studying the accumulation velocity of altmetric data tracked by Altmetric.com

This paper investigates the data accumulation velocity of 12 Altmetric.com data sources. DOI created date recorded by Crossref and altmetric event posted date tracked by Altmetric.com are combined to reflect the altmetric data accumulation patterns over time and to compare the data accumulation velocity of various data sources through three proposed indicators, including Velocity Index, altmetric half-life, and altmetric time delay. Results show that altmetric data sources exhibit different data accumulation velocity. Some altmetric data sources have data accumulated very fast within the first few days after publication, such as Reddit, Twitter, News, Facebook, Google+, and Blogs. On the opposite spectrum, research outputs are at relatively slow pace in accruing data on some data sources, like Policy documents, Peer review, Q&A, Wikipedia, Video, and F1000Prime. Most altmetric data sources' velocity degree also changes by document types, subject fields, and research topics. The type Review is slower in receiving altmetric mentions than Article, while Editorial Material and Letter are typically faster. In general, most altmetric data sources show higher velocity values in the fields of Physical Sciences and Engineering and Life and Earth Sciences. Within each field, there also exist some research topics that attract social attention faster than others.Merit, Expertise and Measuremen

Citation models and research evaluation

Citations in science are being studied from several perspectives. On the one hand, there are approaches such as scientometrics and the science of science, which take a more quantitative perspective. In this chapter I briefly review some of the literature on citations, citation distributions and models of citations. These citations feature prominently in another part of the literature which is dealing with research evaluation and the role of metrics and indicators in that process. Here I briefly review part of the discussion in research evaluation. This also touches on the subject of how citations relate to peer review. Finally, I try to integrate the two literatures with the aim of clarifying what I believe the two can learn from each other. The fundamental problem in research evaluation is that research quality is unobservable. This has consequences for conclusions that we can draw from quantitative studies of citations and citation models. The term "indicators" is a relevant concept in this context, which I try to clarify. Causality is important for properly understanding indicators, especially when indicators are used in practice: when we act on indicators, we enter causal territory. Even when an indicator might have been valid, through its very use, the consequences of its use may invalidate it. By combining citation models with proper causal reasoning and acknowledging the fundamental problem about unobservable research quality, we may hope to make progress.Comment: This is a draft. The final version will be available in Handbook of Computational Social Science edited by Taha Yasseri, forthcoming 2023, Edward Elgar Publishing Lt

The Bibliometric Properties of Article Readership Information

The NASA Astrophysics Data System (ADS), along with astronomy's journals and data centers (a collaboration dubbed URANIA), has developed a distributed on-line digital library which has become the dominant means by which astronomers search, access and read their technical literature. Digital libraries such as the NASA Astrophysics Data System permit the easy accumulation of a new type of bibliometric measure, the number of electronic accesses (``reads'') of individual articles. We explore various aspects of this new measure. We examine the obsolescence function as measured by actual reads, and show that it can be well fit by the sum of four exponentials with very different time constants. We compare the obsolescence function as measured by readership with the obsolescence function as measured by citations. We find that the citation function is proportional to the sum of two of the components of the readership function. This proves that the normative theory of citation is true in the mean. We further examine in detail the similarities and differences between the citation rate, the readership rate and the total citations for individual articles, and discuss some of the causes. Using the number of reads as a bibliometric measure for individuals, we introduce the read-cite diagram to provide a two-dimensional view of an individual's scientific productivity. We develop a simple model to account for an individual's reads and cites and use it to show that the position of a person in the read-cite diagram is a function of age, innate productivity, and work history. We show the age biases of both reads and cites, and develop two new bibliometric measures which have substantially less age bias than citationsComment: ADS bibcode: 2005JASIS..56..111K This is the second paper (the first is Worldwide Use and Impact of the NASA Astrophysics Data System Digital Library) from the original article The NASA Astrophysics Data System: Sociology, Bibliometrics, and Impact, which went on-line in the summer of 200

A bibliometric study of taxonomic botany

AIMS — The aims were: to investigate the citation-patterns of monograph books in taxonomic botany (looking mainly at publications and publishers, and the age of current literature); to provide information for collections management and reference services in libraries that hold botany materials. METHOD — 454 citations were collected from 47 botanical monographs; Impact Factors of journals based on these citations were calculated and compared with conventional Impact Factors from ISI Web of Science; age-distributions of citations were drawn up; other analyses were also carried out. RESULTS — A small Bradfordian core of highly-cited journals was established; monograph Impact Factors were not useable; the important publishers of monograph books were identified; monographs were more often cited than journal articles; older materials were more important than in other sciences; monographs were used by botanists for current awareness purposes; coverage of botanical journals by citation indexes was inadequate. CONCLUSIONS — Librarians should: note the core botanical journals identified here; note the importance of British journals to British botanists; continue to acquire botanical monographs and to retain older materials; display new botanical monographs prominently and include them in current awareness services. PROBLEMS — The small size of the sample means that results were merely indicative. Further studies should: take larger samples; look at citations in journal articles, theses, conference proceedings, etc.; look at citations made over several years. ORIGINALITY — The bibliometrics of taxonomic botany have previously been little studied; likewise citations from monographs. Some of the bibliometric methods of J. M. Cullars were applied to botanical literature

O fator de impacto do ISI e a avaliação da produção científica: aspectos conceituais e metodológicos

Aborda os conceitos e os métodos relacionados com o uso do fator de impacto (FI) do Institute for Scientific Information para avaliação da produção científica publicada em periódicos. Resgata a história do FI, desde sua formulação inicial até tornar-se objeto de inúmeras investigações sobre as diferenças nos valores do indicador nas várias áreas do conhecimento. Destaca que as variáveis que apresentam a maior influência sobre o FI são a densidade e o ritmo de obsolescência dos periódicos. Trata das abordagens sincrônicas e diacrônicas de medir a obsolescência da literatura, como o índice de citação imediata, a meia-vida das citações e o estudo da idade de referências citadas. Conclui com reflexões sobre o sistema de avaliação científica brasileiro e o papel do SciELO na formulação de indicadores bibliométricos. Palavras-chave Avaliação da produção científica; Fator de impacto; Institute for Scientific Information (ISI); Densidade dos artigos; Ritmo de obsolescência da literatura. Impact factor od ISI and evaluation of scientific production: conceptual and methodological aspects Abstract This paper deals with concepts and methods concerning the use of the Impact Factor (IF), as defined by the Institute for Scientific Information (ISI), on the evaluation of scientific production published in specialized journals. The history of IF is discussed from its first formulation up to the moment when it became the subject of a large amount of investigations regarding the differences among the values for different knowledge areas. It is emphasized that the main variables affecting IF are journal density and their obsolescence rate. The synchronous and diachronous approaches used to measure obsolescence are discussed, such as the immediacy index, half-life of citations and citation age. As a conclusion, the Brazilian system for scientific evaluation is analyzed, as well as the SciELO role on the formulation of bibliometric indicators. Keywords Evaluation of scientific production; Impact factor; Institute for Scientific Information (ISI); Literature density; Literature obsolescence rate

Stochastic modeling of responsiveness, schedule risk and obsolescence of space systems, and implications for design choices

The U.S Department of Defense and the National Aeronautics and Space Administration continue to face common challenges in the development and acquisition of their space systems. In particular, space programs repeatedly experience significant schedule slippages, and spacecraft are often delivered on-orbit several months, sometimes years, after the initially planned delivery date. The repeated pattern of these schedule slippages suggests deep-seated flaws in managing spacecraft delivery and schedule risk, and an inadequate understanding of the drivers of schedule slippages. Furthermore, due to their long development time and physical inaccessibility after launch, space systems are exposed to a particular and acute risk of obsolescence, resulting in loss of value or competitive advantage over time. The perception of this particular risk has driven some government agencies to promote design choices that may ultimately be contributing to these schedule slippages, and jeopardizing what is increasingly recognized as critical, namely space responsiveness. The overall research objective of this work is twofold: (1) to identify and develop a thorough understanding of the fundamental causes of the risk of schedule slippage and obsolescence of space systems; and in so doing, (2) to guide spacecraft design choices that would result in better control of spacecraft delivery schedule and mitigate the impact of these "temporal risks" (schedule and obsolescence risks). To lay the groundwork for this thesis, first, the levers of responsiveness, or means to influence schedule slippage and impact space responsiveness are identified and analyzed, including design, organizational, and launch levers. Second, a multidisciplinary review of obsolescence is conducted, and main drivers of system obsolescence are identified. This thesis then adapts the concept of a technology portfolio from the macro- or company level to the micro-level of a single complex engineering system, and it analyzes a space system as a portfolio of technologies and instruments, each technology with its distinct stochastic maturation path and exposure to obsolescence. The selection of the spacecraft portfolio is captured by parameters such as the number of instruments, the initial technology maturity of each technology/instrument, the resulting heterogeneity of the technology maturity of the whole system, and the spacecraft design lifetime. Building on the abstraction of a spacecraft as a portfolio of technologies, this thesis then develops a stochastic framework that provides a powerful capability to simultaneously explore the impact of design decisions on spacecraft schedule, on-orbit obsolescence, and cumulative utility delivered by the spacecraft. Specifically, this thesis shows how the choice of the portfolio size and the instruments Technology Readiness Levels (TRLs) impact the Mean-Time-To-Delivery (MTTD) of the spacecraft and mitigate (or exacerbate) schedule risk. This work also demonstrates that specific combinations/choices of the spacecraft design lifetime and the TRLs can reduce the risk of on-orbit obsolescence. This thesis then advocates for a paradigm shift towards a calendar-based design mindset, in which the delivery time of the spacecraft is accounted for, as opposed to the traditional clock-based design mindset. The calendar-based paradigm is shown to lead to different design choices, which are more likely to prevent schedule slippage and/or enhance responsiveness and ultimately result in a larger cumulative utility delivered. Finally, missions scenarios are presented to illustrate how the framework and analyses here proposed can help identify system design choices that satisfy various mission objectives and constraints (temporal as well as utility-based).PhDCommittee Chair: Saleh Joseph; Committee Member: Brown Owen; Committee Member: Erwin R. Scott; Committee Member: Feron Eric; Committee Member: Mavris Dimitr