I apologize for the delay in responding to your inquiry. Even though it's a little later, I hope the following information will be helpful.
For an ISEF project, you need a project that is challenging and completely original. You need to narrow your vast area of interest to one specific topic that you can investigate with a well controlled experiment. To help you get started, go to the topic selection wizard on the Science Buddies website and answer questions, to help you select a project idea.http://www.sciencebuddies.org/science-f ... deas.shtml
If this doesn’t help, then go to the “Browse the Project Ideas Index,” and look for project ideas with a difficulty of greater than 5. Find a topic that appeals to you and that you would be interested in working on for a few months.
Next try to narrow your topics down to 4-5 topics and then read as much background information as you can, preferably from scientific articles, and look for a specific problem that needs to be solved. The major topic should be of great significance for human health or the environment. You will find a description of problems in the introduction section of research papers as this is where the authors explain why they did the specific research.
You should also review the Science Fair Project Guide from the Science Buddies website to get an idea of all of the steps you will be doing. At this point, you are trying to develop your question, and this is a very critical step that will ensure the success of the rest of the project.http://www.sciencebuddies.org/science-f ... ndex.shtml
If you will let me know what you topics you are thinking about, I can give you some additional specific suggestions that will help you get to the next step.