You need not obtain permission for those who work in the public domain, that is, works with no copyright protection or those with expired copyrights. Academic honesty, however, mandates that you acknowledge all sources in your dissertation, even those in the public domain. If you use copyrighted material in your dissertation, you must secure the permission from the owner to include it unless it falls under the doctrine of fair use, which allows limited reproduction of copyrighted works for educational and research purposes .This doctrine is rather complex and can have many interpretations. Miller and Taylor (1987) reported that most university style manuals permit “excerpts of up to 150 words, provided they do not constitute a major portion of the original works”.
If you believe that what you are using falls under fair use, you need not obtain permission, but you must cite the sources in footnotes or in endnotes and in references. Using copyrighted material in your dissertation without obtaining permission can be copyright infringement and is called piracy if you profit from it in any way. Both are serious infractions. Be sure to always obtain written permission from the author or permission from the author or publisher if you plan to use copyrighted material in your dissertation, such as tests, questionnaire, poems, figures, or other artworks, or large excerpts of books. Madsen (1992) explained the process for obtaining permission:
Send the holder of the copyright – usually the publisher of the book or article – a simple form listing the work , the pages and lines you wish to copy and quote, and the title and the publisher of the work in which the material will be published . A form also should include a place for the copyright holder’s signature.
This procedure probably will be necessary if you later decide to publish an article or write a book based on your dissertation . Should you wish to pursue more in depth information about the copyright law, refer to William S.strong’s (1998) The copyright book: A practical guide.