Altmetrics and Open Access: A Measure of Public Interest

Researchers, research managers and publishers are increasingly required to factor into their policies and practices the conditions by which publicly funded research must be made publicly available. But in the struggle for competitive funding, how can researchers provide tangible evidence that their outputs have not only been made publicly available, but that the public is using them? Or how can they demonstrate that their research outputs have reached and influenced those whose tax dollars have helped fund the research?