Actuality and Obsolescence of Scientific Literature

In order to explain the much increased citation frequency of recently published articles in respect to the normal exponential decay of older articles, the scientific information diffusion theory is used. The obsolescence rate results by combining the Gaussian normal distribution with the exponentially decreasing rate of the number of, articles with age. For recently published works supplementary adjustments are necessary: first, in order to have the citation number start at zero at the start of counting, and second, in order to reach the sixfold citation climax two years before it. All peculiarities exhibited by experimental survey data have been properly reproduced by making plausible assumptions suggested by the diffusion theory, such as preference of virtual authors to directly read recent articles, preference for verbal cross-communication with colleagues, and increased preference for the newest articles in fields of personal interest. The latter preference is damped in the case of older articles since virtual authors prefer to consult the scientific community or review books. The results do confirm once more the reliability of the scientific information diffusion model.