Think about subjects that interest you and that you have been good at. If you choose a dissertation topic that interests you, you’ll be more likely to stay committed to the research process, and also more likely to stay engaged and motivated as you work to complete your studies.
I examined past coursework, as well as research papers to see which topics piqued my interest. Using these can be a good base for a dissertation topic if these are your previous academic successes and interests.
Review PhD literature in your field of study for trends and gaps, and consider what the current technology constraints will be in your field of study. Reading what others have done will show you what has already been done and what doesn't need added, and will help you to focus on a narrow area.
Check the existing literature for the gaps which you can fill with your dissertation. If you can choose a topic that fills these gaps in a way that will make a contribution to your field, if you can make a splash with your research.
Talk to your academic advisor about which topics you are discussing. In some ways, they can help you refine your ideas because they have expertise and knowledge of the field.
Your advisor may help assess the feasibility of your proposed topics. They will also bring their experience delving deep into a topic to feed back on the scope, available resources, and some chances it could confront.
Be sure to do enough research on your chosen dissertation topic so that it is within an acceptable scope. If the topic is too broad you get overwhelmed by it, while if it is too narrow there is no research material available.
See if your chosen topic has availability of resources and data. Make sure you have the resources (materials, databases and research tools) to do your dissertation work.
Select a topic that is both of interest to you and is useful to your field of study. There you go, adding more weight to your research by making it more significant and impactful by using a topic with a real life application.
Imagine what kind of direction your contemplated topic could spark further research in. Your dissertation topic should not only be relevant to your ongoing work, but you should be able to build on it later in your field of study.
A successful research experience starts with the right dissertation topic. Having an idea of where you want to go in your research helps you think of a topic, as well as the details of the execution when you decide to begin an academic journey. With time, make an informed decision and your dissertation will be a mosaic of your field.