Before selecting a topic, you must first determine whether you are enthusiastic about the topic. A dissertation requires deep, sustained engagement. If you lack the passion for your topic, you may experience writer's block or burnout. You may have selected a topic based solely on your interest, but this backward approach will likely frustrate your potential advisor. There are other criteria for choosing a topic. Make sure it has something to do with your discipline or interests.
While considering potential topics, take into account the amount of time and money you have available to complete your dissertation. Choose a topic that fits the timeframe you have available, the scope of your research, and the practicalities of conducting the research. If your topic is too broad or has too many variables, you may want to consider narrowing it, expanding it, or shifting it slightly. Make sure to research previous dissertations that explore the topic.
You can also replicate previous studies on a topic. Although many students are put off by the idea of repeating something they already know, this practice is actually one of the best ways to add strength to your research. But be sure to avoid studies that are trivial, incomplete, or incorrect. That way, you can be sure to create a unique piece of knowledge that will stand out in the crowd. And don't forget to be creative and innovative!