arXiv subjects

Anthony F. J. van Raan

Publications and source records attributed to Anthony F. J. van Raan.

26 records · Page 2Linked to original sources

arXiv2009

Is scientific literature subject to a sell-by-date? A general methodology to analyze the durability of scientific documents

The study of the citation histories and ageing of documents are topics that have been addressed from several perspectives, especially in the analysis of documents with delayed recognition or sleeping beauties. However, there is no general methodology that can be extensively applied for different time periods and/or research fields. In this paper a new methodology for the general analysis of the ageing and durability of scientific papers is presented. This methodology classifies documents into three general types: Delayed documents, which receive the main part of their citations later than normal documents; Flash in the pans, which receive citations immediately after their publication but they are not cited in the long term; and Normal documents, documents with a typical distribution of citations over time. These three types of durability have been analyzed considering the whole population of documents in the Web of Science with at least 5 external citations (i.e. not considering self-citations). Several patterns related to the three types of durability have been found and the potential for further research of the developed methodology is discussed.

physics.soc-ph↗

arXiv2008

Scaling rules in the science system: influence of field-specific citation characteristics on the impact of individual researchers

The representation of science as a citation-density landscape and the study of scaling rules with the field-specific citation-density as a main topological property was previously analysed at the level of research groups. Here the focus is on the individual researcher. In this new analysis, the size-dependence of several main bibliometric indicators for a large set of individual researchers is explored. Similar results as those previously observed for research groups are here described for individual researchers, reinforcing the idea of prevalent scaling rules in the representation of science as a citation-density landscape. Differences among thematic areas with different citation densities are discussed.

physics.soc-ph↗

arXiv2008

Self-citation as an impact-reinforcing mechanism in the science system

In previous papers it was demonstrated that lower performance groups have a larger size-dependent cumulative advantage for receiving citations than top-performance groups. Furthermore, regardless of performance, larger groups have less not-cited publications. Particularly for the lower performance groups the fraction of not-cited publications decreases considerably with size. These phenomena can be explained with a model in which self-citation acts as a promotion mechanism for external citations. In this article we show that for self-citations similar size-dependent scaling rules apply as for citations but generally the power law exponents are higher for self-citations as compared to citations. We also find that the fraction of self-citations is smaller for the higher performance groups and this fraction decreases more rapidly with increasing journal impact than for lower performance groups. An interesting novel finding is that the variance in the correlation of the number of self-citations with size is considerably less than the variance for external citations. This is a clear indication that size is a stronger determinant for self-citations than for external citations. Both higher and particularly lower performance groups have a size-dependent cumulative advantage for self-citations, but for the higher performance groups only in the lower impact journals and in fields with low citation density.

physics.soc-ph↗

arXiv2007

Scaling rules in the science system: influence of field-specific citation characteristics on the impact of research groups

We propose a representation of science as a citation-density landscape and investigate scaling rules with the field-specific citation density as a main topological property. We focus on the size-dependence of several main bibliometric indicators for a large set of research groups while distinguishing between top-performance and lower performance groups. We demonstrate that this representation of the science system is particularly effective to understand the role and the interdependencies of the different bibliometric indicators and related topological properties of the landscape.

physics.soc-ph↗

arXiv2007

Bibliometric statistical properties of the 100 largest European universities: prevalent scaling rules in the science system

For the 100 largest European universities we studied the statistical properties of bibliometric indicators related to research performance, field citation density and journal impact. We find a size-dependent cumulative advantage for the impact of universities in terms of total number of citations. In previous work a similar scaling rule was found at the level of research groups. Therefore we conjecture that this scaling rule is a prevalent property of the science system. We observe that lower performance universities have a larger size-dependent cumulative advantage for receiving citations than top-performance universities. We also find that for the lower-performance universities the fraction of not-cited publications decreases considerably with size. Generally, the higher the average journal impact of the publications of a university, the lower the number of not-cited publications. We find that the average research performance does not dilute with size. Large top-performance universities succeed in keeping a high performance over a broad range of activities. This most probably is an indication of their scientific attractive power. Next we find that particularly for the lower-performance universities the field citation density provides a strong cumulative advantage in citations per publication. The relation between number of citations and field citation density found in this study can be considered as a second basic scaling rule of the science system. Top-performance universities publish in journals with significantly higher journal impact as compared to the lower performance universities. We find a significant decrease of the fraction of self-citations with increasing research performance, average field citation density, and average journal impact.

physics.data-an↗

arXiv2006

Comparison of the Hirsch-index with standard bibliometric indicators and with peer judgment for 147 chemistry research groups

In this paper we present characteristics of the statistical correlation between the Hirsch (h-) index and several standard bibliometric indicators, as well as with the results of peer review judgment. We use the results of a large evaluation study of 147 university chemistry research groups in the Netherlands covering the work of about 700 senior researchers during the period 1991-2000. Thus, we deal with research groups rather than individual scientists, as we consider the research group as the most important work floor unit in research, particularly in the natural sciences. Furthermore, we restrict the citation period to a three-year window instead of life time counts in order to focus on the impact of recent work and thus on current research performance. Results show that the h-index and our bibliometric crown indicator both relate in a quite comparable way with peer judgments. But for smaller groups in fields with less heavy citation traffic the crown indicator appears to be a more appropriate measure of research performance.

physics.data-an↗

arXiv2005

Performance-related differences of bibliometric statistical properties of research groups: cumulative advantages and hierarchically layered networks

In this paper we distinguish between top-performance and lower performance groups in the analysis of statistical properties of bibliometric characteristics of two large sets of research groups. We find intriguing differences between top-performance and lower performance groups, but also between the two sets of research groups. Particularly these latter differences are interesting, as they may indicate the influence of research management strategies. Lower performance groups have a larger scale-dependent cumulative advantage than top-performance groups. We also find that regardless of performance, larger groups have less not-cited publications. We introduce a simple model in which processes at the micro level lead to the observed phenomena at the macro level. Top-performance groups are, on average, more successful in the entire range of journal impact. We fit our findings into a concept of hierarchically layered networks. In this concept, the network of research groups constitutes a layer of one hierarchical step higher than the basic network of publications connected by citations. The cumulative size-advantage of citations received by a group looks like preferential attachment in the basic network in which highly connected nodes (publications) increase their connectivity faster than less connected nodes. But in our study it is size that causes an advantage. In general, the larger a group (node in the research group network), the more incoming links this group acquires in a non-linear, cumulative way. Moreover, top-performance groups are about an order of magnitude more efficient in creating linkages (i.e., receiving citations) than the lower performance groups.

physics.soc-ph↗

arXiv2003

Reference-Based Publication Networks with Episodic Memories

In this paper we report first results of our study on network characteristics of a reference-based, bibliographically coupled (BC) publication network structure. We find that this network of clustered publications shows different topologies depending on the age of the references used for building the network. A remarkable finding is that only the network structure based on all references within publications is characterized by a degree distribution with a power-law dependence. This topology, which is typical for scale-free networks, disappears when selecting references of a specific age for the clustering process. Structuring the publication network as a function of reference age, allows 'tuning through the episodic memory' of the nodes of the network. We find that the older the references, the more the network tends to change its topology towards a Gaussian degree distribution.

cond-mat.stat-mech↗