This is the most important moment in all your years of schooling. You have written your dissertation, comprised of long hours of research and hard work. Now you have to defend it. This may not be the most difficult part (writing your dissertation is impressive in itself), but you need the approval of the committee to pass. You will either be told that you've passed, that you need to make revisions, or that you will not be approved.
To ensure your success, you need to create an effective opening statement. Try to think of it as exciting and not nerve-wracking. You've created and nurtured your project. Now it's time to show off and tell them what you've learned!
Some openings go straight to the question-and-response process, but your advisor should prepare you if this is the case, as it can completely change how you plan to defend your dissertation. Just be ready to answer questions at the end. If they happen to ask questions first, all you have to do is bring what you thought would be at the end of your discussion to the front of it.
You will want to create a solid opening so that you can control how the conversation begins (whenever that may be). Your opening should include the most significant parts of your research. Summarize your paper, what it brings attention to, and its important points.
To start, you may want to create an outline. Go through your paper and write down the parts that you think are best to include in your statement. If it's more information that you could possibly fit, go over the list and simply it. If need be, go over it a final time to make sure you have everything you want to mention.
You should state your central theme, argument or idea in your dissertation opening. You will want to make a strong, confident point and statement. You want to spark interest as this will be the introduction to your defense, and will bring questions from the committee.
How you begin will shape the rest of your defense, so while there is no content requirement, it should be worded carefully. If you want it to go in a certain direction, you must first lead it there. Plan or write (or do both) your opening in a way that will best serve you. Let it be your guide to taking control of the discussion that will follow!