A good research topic addresses a specific question or problem in a meaningful way. Good research topics answer questions, such as who, what, when, where, why and how, about the subject.
Two common pitfalls in choosing a research topic are finding very little research on the subject or discovering that the research doesn't support the thesis. These pitfalls can be avoided by doing preliminary searches before settling on one research topic. A good research topic has a somewhat narrow focus. If the topic can be summed up in a few words, it is too broad. It is most likely also too broad if the writer has trouble deciding on a succinct thesis statement.