Generally, yes. You own the copyright to your thesis, which means you may reuse the work however you see fit as long as your reuse does not impact the University's ability to host a copy of the thesis on UWSpace (remember, you are required to provide a non-exclusive distribution licence to the University). If you did want to publish parts of your thesis as a journal article or as part of a scholarly book, you would also be responsible for clearing the copyright of any third-party materials (including images, figures, tables, and longer quotations) in the later manuscript.
A couple of points to keep in mind:
- While most academic publishers and journals have stipulations about considering previously published work, including work published in electronic format, submissions derived from a thesis are not usually included in this category, even when a thesis is publicly available through an institutional repository like UWSpace. For example, Elsevier does not consider work published in a thesis to be prior publication. In any case, make sure you check the publisher and journal policies before you submit work based on your thesis, and follow the directions the journal provides. If you are writing a cover letter for your submitted work, it can be helpful to include a statement indicating that the work is based on your publicly available thesis in case the journal editors have any concerns about overlapping content.
- Journals do not typically require authors to declare when a submission derives from a thesis, whereas book publishers will likely want to know upon submission not only if a manuscript was based on a thesis but also, if it is, how the project evolved from thesis to book manuscript. (For more on the necessary evolution from thesis to book manuscript, see the "Manuscripts Based on Dissertations" page at the website for McGill-Queen's University Press).
- Some print-on-demand/vanity publishers reach out to recent thesis authors to offer their services to publish your thesis as a book. These services do not provide editorial or peer review of your work. They simply add a cover to the thesis and place it on their website and other book-selling sites. Since your thesis will also be available for free on UWSpace, there is little incentive for others to buy it from an external publisher, especially if the two versions are identical. Theses can certainly be the basis for a scholarly book, but such books are subject to peer review and need substantial revision to make the content suitable to a wider audience. Read What is a vanity publisher and why does it matter? for more information.