While there is no PROOF that Dramatica is 100% accurate (it's just a theory, you know), there are a number of things you can do to give you confidence that the theory is correct:

1. Try it on your own story. This has been one of the most effective methods of demonstrating Dramatica's power. By understanding Dramatica's questions and answering them, Dramatica will "predict" certain things about your story that you didn’t provide in your answers. Generally, for a story that doesn’t have structural problems, these answers will line up with what you know to be true. That usually gives you the confidence to try Dramatica on one of your stories that has problems you're trying to work out.
2. Carefully examine the example stories. Open some of the excellent stories, like The Verdict or Hamlet (or a story you're familiar with) and look at the StoryPoints window. There you will have a summary of structural points about the story, and you can read the storytelling that illustrates those points. Compare what you know about the story to Dramatica's perspective. Does it make sense? Is it insightful? This is a great way to see and learn about Dramatica's concepts in action.
3. Attempt to make a different storyform match an example story. For hard-core skeptics who want to take active steps to disprove the validity of the theory, try this little exercise: Choose one of our example stories, one you're familiar with. Create a new story document, and select one of the 32,768 storyforms at random (you can either use the "Spin-the-Model" feature or just randomly answer questions). Now, try to illustrate the key structural points in the StoryPoints window, and see if you can make the storyform you've selected make sense for example story you've chosen. In other words, can you pick another very different storyform and illustrate it to make as much sense as the storyform for, say, The Verdict? If you can make random choices sound as good as a storyform created by careful analysis, then you've just created substantial doubt as to the validity of that storyform. If you can do it for many stories, you've shot down the theory. Good luck.