Hermann Schier | Searcharxiv

arXiv2018

Algorithmically generated subject categories based on citation relations: An empirical micro study using papers on overall water splitting

One important reason for the use of field categorization in bibliometrics is the necessity to make citation impact of papers published in different scientific fields comparable with each other. Raw citations are normalized by using field-normalization schemes to achieve comparable citation scores. There are different approaches to field categorization available. They can be broadly classified as intellectual and algorithmic approaches. A paper-based algorithmically constructed classification system (ACCS) was proposed which is based on citation relations. Using a few ACCS field-specific clusters, we investigate the discriminatory power of the ACCS. The micro study focusses on the topic "overall water splitting" and related topics. The first part of the study investigates intellectually whether the ACCS is able to identify papers on overall water splitting reliably and validly. Next, we compare the ACCS with (1) a paper-based intellectual (INSPEC) classification and (2) a journal-based intellectual classification (Web of Science, WoS, subject categories). In the last part of our case study, we compare the average number of citations in selected ACCS clusters (on overall water splitting and related topics) with the average citation count of publications in WoS subject categories related to these clusters. The results of this micro study question the discriminatory power of the ACCS. We recommend larger follow-up studies on broad datasets.

cs.DL↗

arXiv2006

Using time dependent citation rates (sales curves) for comparing scientific impacts

As a simple means for comparing and - if possible - predicting scientific impacts of different researchers working in the same field, we suggest comparing their "sales curves". A sales curve is the number of citations of the researcher's papers per year, the citation rate, considered as a function of time. As examples, we present the citation histories of 10 older well-cited scientists working in the same field. The sales curve is found to be highly individual, that is, there is a large variation between different scientists' sales curves. For each well-cited scientist, however, the sales curve is steadily increasing as long as he is young and active, and its slope, the citation acceleration, contains the essential information about his impact. The slope averaged over the time of activity of the scientist is roughly independent of time and is a fairly age-independent measure of his scientific impact. In physics and chemistry, well-cited active scientists have time-averaged citation accelerations at the order of 10 citations per year^2 or more. The normal citation acceleration is an order of magnitude smaller. We also show the sales curves for three large research institutes whose sizes have been fairly constant over the last 35 years. These sales curves are quite linear and have slopes at the order of 1 citation per scientist per year^2.

physics.soc-ph↗