Should I submit my IB Extended Essay or another research paper with my application?

Generally speaking, it would not do a lot of good for you to submit an entire IB extended essay or an additional research paper with your application. The demands of reviewing over 18,000 applications in just 10-12 weeks do not allow us the time to review lengthy supplemental materials. It is understandable that you are very proud of your work on these projects, and if you are convinced that you would not be putting your best foot forward on the application without submitting them, then you should limit yourself to submitting a one-page abstract summarizing the paper or project. A multi-page research paper or presentation will not be reviewed by the Admissions Committee or forwarded to the faculty for evaluation.