Abstract: [Purpose/Significance] The birth of the Internet has brought revolutionary impact on bibliometrics, giving rise to a number of online download indicators for academic literature. The most representative basic indicator among them is the download frequency, but it also includes the annual download rate, the total download volume, the download half-life, and the Google Scholar Index. The proposal of these indicators provides a new method and means of measuring scholarly dissemination and impact, which is a significant development of traditional bibliometrics and an important component of alternative metrics. Given the lack of indicators that comprehensively characterize the dissemination, impact, knowledge and information volume of academic journals, this paper proposes the download factor indicator to address this problem. [Method/Process] First, according to the changes of download frequency and citation frequency over the years, based on the citation data of CSSCI journals of library information and bibliology on CNKI, a panel data model was used to establish a prediction model of download frequency and citation frequency, and the optimal lag period for designing the download factor was determined. The indicator of download factor was proposed, that is, the average number of downloads per hundred times of each paper after 2 years of publication. This paper further used ridge regression to analyze the relationship between the download factor and the impact factor, h-index, and the number of articles. [Results/Conclusions] The download frequency with a lag of 1 year and 2 years determines 80% of the citation frequency. This article innovatively adopts a panel data model and comprehensively evaluates the impact of download frequency on citation frequency in both current and lagged periods, thereby greatly improving the prediction accuracy. The download factor can better measure the knowledge information volume, dissemination level, influence and academic quality of the journal. The timeline for downloading factor indicators is synchronized with the influencing factors, both within 2 years after the publication of journal articles, focusing on the evaluation of academic communication level. The download factor has the highest correlation with the main indicator of the impact of journal quality, the h-index, and has a high correlation with the impact factor and publication volume. It has good statistical indicator properties and is a comprehensive indicator for evaluating journals; the download factor index needs to be more inspection of application in disciplines and use of data. This article is based on the conclusions drawn from the research of 19 CSSCI journals in library and information science literature. The relationship between download frequency and citation frequency in other disciplines, as well as the construction of download factors, require further research in conjunction with the latest data.

Key words: download factor, level of dissemination, lag period, evaluation indicator