Before you decide on a PICOT question, you should test it--do a quick search in a library database to see if there are enough published articles on your topic. If a lot of articles come up, then you probably have a good PICOT question to use for your assignment. If only two or three or no articles come up, then you will need to adjust your PICOT question or choose a completely different question.
Example:
You want to write about meditation as an intervention for cancer patients.
Go to the library nursing database CINAHL Complete. Enter a search using basic keywords:
meditation AND cancer AND patients
The results for that search show over 200 articles. That's a good sign that enough has been written about the topic to make it a good PICOT question--you will have enough articles to use for your assignment.
Next, see if you can spot several articles in your results list that have been written in the last 5 years (you'll see a year listed for each article--look in the information below the article title to find the year).
Also, look through some of the articles you found to make sure they are primary (evidence-based) research articles. Here's a guide for identifying primary (evidence-based) research articles.
If you do a basic search in a library database and almost no useful-looking results come up, that's usually a sign that you have to change your PICOT question.