1) The document discusses open science and making scientific data, research, and dissemination available to all through open access, open repositories, and open source. It highlights benefits like reproducibility, credibility, and faster progress.
2) There are two main flavors of open access - gold OA journals and green OA repositories. Gold OA journals do peer review while green OA repositories allow archiving of articles from both OA and traditional journals.
3) Barriers to open data include sociocultural factors like a lack of training and norms, as well as practical barriers like the time and costs involved and a lack of incentives for researchers. However, open data also faces opposition from some publishers.