The idea of Open Access has been debated extensively in recent years. In the past, it has largely been a personal choice whether or not to make all of your papers and talks openly available, but increasingly there is government pressure to move in this direction.
In particular, HEFCE introduced a new rule on Open Access Research which became effective from April 1, 2016:
Journal articles and articles in conference proceedings will only be eligible for submission in the next REF if they have been deposited in an institutional or subject repository within 3 months of being accepted for publication.
Additional Oxford University information on this requirement is available here, and elsewhere on the Open Access Oxford website.
What should you do? The answer is to deposit your paper in Symplectic. The University libraries team will check publisher permissions, create an ORA (Oxford Research Archive) record and make the full-text available if and when it complies with the requirements of your publisher.
You are free to also make the paper available on your own webpage and/or arXiv, but doing this on its own is not acceptable -- the university has decided that everyone must put papers on Symplectic/ORA because that will streamline the process for the next REF.
Although the new rules apply only to papers accepted from April 1, 2016, because it will streamline the REF process, the department would like everyone to also deposit all earlier papers accepted since the publication cutoff date for the last REF -- Dec 31, 2013.
Depositing your paper in ORA using Symplectic
Don't forget your data
At the same time as depositing your final paper in ORA, you should also remember to deposit your "supporting data" in ORA-data.
This is a separate requirement which was initially for those with EPSRC research funding but is now required under the university's Policy on Research Data Management.
For more details, see here.