The purpose of this research is to examine the impact on usage of the journal Nucleic Acids Research (NAR) moving to an open access model. A major objective was to examine the impact of open access in the context of other initiatives that have improved accessibility to scholarly journals. The study also aims to demonstrate the potential of deep log analysis for monitoring change in usage over time.
Data were gathered from the logs for the period 2003‐June 2005 and analysed using deep log methods. The data were analysed to provide the following information on use: type of item viewed; usage over time; usage for individual journal issues; usage per type of article; age of article. Usage analyses were further examined with regard to the following user characteristics: subscriber/non‐subscriber; referrer link employed, organisational affiliation; geographical location.
The analysis showed that the rise in use of NAR over the survey period (140 per cent) could largely be attributed to the opening up of the site to search engines and that the move to OA had a relatively small influence on driving usage up further (less than 10 per cent).
The study for the first time thoroughly analyses the usage data of a significant experimental open access journal and reveals the huge impact of search engines on driving up usage.
