Hybrid open access—A longitudinal study

« This study estimates the development of hybrid open access (OA), i.e. articles published openly on the web within subscription-access journals. Included in the study are the five largest publishers of scholarly journals; Elsevier, Springer, Wiley-Blackwell, Taylor & Francis, and Sage. Since no central indexing or standardized metadata exists for identifying hybrid OA an explorative bottom-up methodological approach was developed. The individual search and filtering features of each publisher website and a-priori availability of data were leveraged to the extent possible. (…) »