While working on a Masters Degree in Data Analytics I submitted two original research papers (quasi-opinion pieces) to my then University's digital repository. Both were accepted. I am the sole author. I would now like to publish them formally. Can I submit them to journals or deposit them in other repositories as well?
From the viewpoint of a university's institutional repository, it would not be unethical or unacceptable for authors to submit their work to a journal or another repository. The purpose of repositories is to provide unrestricted and immediate access to research. Submitting work to more than one repository is another way for an author to increase accessibility to his/her work. Moreover, there are different kinds of open repositories: institutional repositories, subject-specific repositories, and multidisciplinary repositories. Each of these has a different function, and submitting your work to multiple repositories would only increase its outreach.
Regarding publication in a journal, it is perfectly acceptable, and in fact desirable to publish a preprint in a journal. Preprints are not publications: they are just a way to give people access to your research. For your work to gain the stamp of credibility, it must be published in a peer reviewed journal.
However, there may be some restrictions and/or specifications at the journal end about submitting papers that have been deposited in a repository. Most journals allow authors to deposit pre-prints of their work that do not contain any edits or revisions from the publication process in open repositories. Others allow authors to deposit preprints of their work that have been revised to show the revisions made in the publication process, and a few journals allow authors to deposit the final publisher's version of the article. Some publishers have an embargo period and allow authors to deposit their work in a repository only a few months after publication. You should go through your target journals instructions for authors carefully before you submit your paper.
You might be interested in reading the following articles:
- How to make your paper more accessible through self-archiving
- A young researcher's guide to open access publishing
- The role of preprints in research dissemination