Abstract: Who participates in open-access publications and open-science research? This course – based on ongoing IMLS and Mellon Foundation supported research and education projects – is for researchers, practitioners and administrators wishing to understand, interpret, analyze, or measure participation in open scholarly activities. Over three sessions, we will examine quantitative measures of open science and open access outputs; measures of international diversity; and measures of gender bias. Each session will include a discussion of core concepts and measures, key summary reports and databases, and quality and reliability measures. Each session will be divided into three parts so that attendees can choose to engage the subject at the depth appropriate to their needs. The first part of each session – for all attendees – will cover core concepts and summary sources. This part is sufficient for those who wish to locate, understand and interpret existing summary reports and interactive websites to identify benchmarks and trends. The second hour of each section will focus on exercises analysis using interactive R notebooks to analyze participation data retrieved from open APIs. This part will be of interest to those with an interest in conducting their own data analyses. The third part of the course is intended for those planning to actively collect new data within their own institutions or projects, and will focus on specific data-collection scenarios – based on a pre-course survey of enrolled participants. Audience: Researchers, librarians, faculty/scholars, administrators