While it seems like an arbitrary step, having a bank of keywords to reference when inputting a search is valuable in making sure you are capturing every possible resource available to you. In addition to pulling keywords from your topic and research questions, you'll want to think as well about related ideas and concepts, and synonyms for your keywords. Sometimes authors use different words or phrasing, and so having a bank of keywords to exchange and try out can help you make sure you aren't leaving anything out.
Remember: There is no such thing as a perfect search. You are not going to capture everything you need in one go. Think of research as a puzzle in this way, you have to sometimes go through each piece to find the one that fits and gives the results you desire.
As you are reading and looking through sources, keep an eye out for other words and ideas you could be searching to help drive your topic along.
Concept mapping is one brainstorming technique you can use to start forming your list of keywords and search terms.
When you have a starting list of keywords and terms to search, it's important to also be aware of how to effectively input these keywords into a search engine. Boolean operators (AND, OR, NOT) are often used between keywords or phrases, but there are other tricks to be aware of such as truncation, nesting, and quotation marks.
Additionally, take advantage of the advanced search's ability to let you search different fields which can help for more targeted searching. Different databases will have different options so make sure you explore a database to it's fullest to see what options it has that might help you narrow down your search.
Subject searching in particular can help yield highly relevant results by searching your keywords in the subject field of the advanced search. Sources are tagged with subject terms that best match what the item is about similar to how hashtags can be used in social media posts. Therefore, they give a quick way to see what topics an item covers, but they are also usually hyperlinked so you can find other items tagged with the same subject term.
In order to be thorough in your research, you'll need to search in more than one place. Even APPsearch, won't be able to capture everything that might be relevant and pertinent to your search. So it is helpful to have a plan of where you plan to do some searching. This can include general places such as APPsearch, the library catalog, and Google Scholar. You might also identify discipline specific databases to search or databases that have a certain source type that fits your information need (for example, newspapers).
Once you've identified what you want to search and where you want to search, you can help keep yourself organized by creating a search log. This will help to ensure that you are not duplicating your efforts as well as give you a view of what you've already tried when searching. Remember you might try the same search across different databases and get different results.
Here is an example that you can view and retool to fit your research habits: