As well as discussing theoretical ideas within an essay, you can use a theoretical perspective or approach as a framework if you are doing research of your own, such as a dissertation. Think of this as a way of using existing knowledge to guide you in researching your topic – you’re not just considering every aspect of your topic at random, but using a theory to look at it in a particular way.
It’s also important not to get theory confused with methodology. Your chosen theory might shape your approach to your research topic, or the ways in which you think about it, whereas your methodology can be thought of as the actual tools or processes that you use to conduct the research. For more examples of the differences between the two, see this piece on using theory in academic research.
When writing about your use of theory in research, try to remember the following key points:
For more detailed help on using theory in research, view this guide from Sacred Heart University.
Summary
When using theory in research, think of it as a framework that guides your approach to your topic, or helps you think about it from a particular perspective. There won't be a 'right' or 'wrong' theory to use, but you should choose a theoretical perspective that is relevant and that you can justify using.