Variation of the half-life of literature in the population of references cited in geographical journals in the age of the publication explosion

Abstract

The article concludes the first part of the author's investigations into the half-life of literature - a concept having become popular in informatics for supposedly measuring the rate of obsolescence of scientific and technical literature — and its variations. At the macro-level the study was based on natural science journals, at the meso-level on geographical journals. As an approval test of the past investigations the article presents the variation of the half-life of literature in the population of references cited in geographical journal articles published in 1939 and in 1969.

The main results of the approval test are:
1. in the period investigated the average size of geographical journal articles has hardly changed, while the average number of references per article has doubled;
2. the half-life of the increased population of references has, in generál, not decreased, but increased, on the average by 15%;
3. the average age of life of the increased population of references has, in general, not decreased, but increased on the average by 18%.
The results of the approval test are completely in conformity with the conclusions of the author's investigations published so-far, confirm his former results and refute the notion of the half-life of literature and the ídeas about the variation of the half-life prevalent nowadays in the public opinion.
The investigations will be continued in the future on the micro-level of articles and references, and will close by the study of the theoretical problems involved.