Worldwide use and impact of the NASA Astrophysics Data System digital library

Abstract

, has developed a distributed online digital library which has become the dominant means by which astronomers search, access, and read their technical literature. Digital libraries permit the easy accumulation of a new type of bibliometric measure: the number of electronic accesses ("reads") of individual articles. By combining data from the text, citation, and reference databases with data from the ADS readership logs we have been able to create second-order bibliometric operators, a customizable class of collaborative filters that permits substantially improved accuracy in literature queries. Using the ADS usage logs along with membership statistics from the International Astronomical Union and data on the population and gross domestic product (GDP), we have developed an accurate model for worldwide basic research where the number of scientists in a country is proportional to the GDP of that country, and the amount of basic research done by a country is proportional to the number of scientists in that country times that country's per capita GDP. We introduce the concept of utility time to measure the impact of the ADS/ URANIA and the electronic astronomical library on astronomical research. We find that in 2002 it amounted to the equivalent of 736 full-time researchers, or $250 million, or the astronomical research done in France.

Usage impact factor: The effects of sample characteristics on usage‐based impact metrics

“…Bollen and Luce (2002) and Bollen, Van de Sompel, Smith, and Luce (2005) proposed the use of social network metrics calculated for journal networks derived from usage sequences in a library's access log. Kurtz et al (2004aKurtz et al ( , 2004b discussed the potential of usage data for impact ranking. Brody, Harnad, and Carr (2006) later explored how early article usage statistics can predict citation rates.…”

The Emerging Scholarly Brain

“…Two examples of their use, both taken from the ADS Topic Search (adsabs.harvard,edu/cgibin/TopicSearch), will serve as an illustration. Here we will use the language of networks, Kurtz, et al (2005) use the language of lists of attributes. Both examples find information about a technical topic, while this can be almost anything, for concreteness we'll use the topic "weak lensing."…”

Mapping the structure of science through usage

“…BOLLEN & LUCE (2002) and BOLLEN et al (2005) discuss methods to derive metrics of journal and article impact from recorded digital library usage data. KURTZ et al (2004aKURTZ et al ( , 2004b study the temporal relation between reading and citation rates and formulate a model for the prediction of researcher productivity from present readership rates.…”