Library databases are not answer machines. You cannot type your research question into a library search engine and get a bunch of articles that answer it. That is not how databases work.
Instead, you need to think like a computer. Whatever you type into the search box, the database is going to match it.
You need to think strategically about your research question and what words might appear in articles that would be useful to you. This is where keyword searching comes in.
You are probably wondering why you would need to use alternative keywords. Sometimes switching the words you use while doing a search can actually pull up more results.
Take each of your keywords and try to come up with synonyms for them. List as many as you can. Here is an example:
Use some of these alternative search terms. Mix and match when doing a search to see what brings up the most relevant information.
You can also look at the subject terms assigned to an article to find more relevant search terms.