Hello,

Unfortunately there are no "good" or "bad" topics defined merely in terms of quantitative and qualitative analysis because as such these concepts are "empty". They need a context and a focus. You can't have any analysis without a) personal interests, b) research problems, c) identified points of view, d) data.

The combinations of quantitative and qualitative approaches are frequently introduced as triangulation. Conference proceedings and other collections of articles on your field may work as a starting point, but as I mentioned, you need to develop the idea by yourself.

You are talking about a Mixed Methods Study. Do some research on the different types of mixed and start from there. No one can tell you a good topic when this is going to be your study. You have to find that good topic.

Would anything in the area of psychology in prisons be of interest to you? Find some specific topic that interests you personally, like the colleagues above recommended, and start outlining your research problem, question, then choose appropriate methods, conceptual framework, etc. Good luck!