Author : E. S. Hellman
A statistical analysis of usage data for open-access ebooks from two different publishers and from a free ebook distribution platform indicates that open-access ebook usage is distributed following log-normal statistics, and meaningful analysis results after calculating the logarithm of the download counts.
To assess usage impact from raw usage data in alignment with the goals of open-access ebook publishing, future impact analyses should use logarithm-based metrics to measure an “open-factor”.