I would add, explanatory ability of the event which would be foremost on the list.I'm asking for your criteria. Maybe you don't understand what that means? It has to be some value or standard you can name independently of any specific theory, that you can then use to assess the quality of a theory being evaluated.
Here are some examples others have already given in the thread so far:
• Predictive power
• Consistency (with existing knowledge and accepted theories)
What are your criteria for IBE?