<p>@pacific34: The Caltech admissions committee tries to admit those students who they think are most likely to do well in their classes, pursue interesting research projects, graduate on time, go on to do impressive things after they graduate, etc. What they do NOT care about is vindictively applying an arbitrary standard. </p>
<p>This means that they will not reject you simply because you could not take a particular examination, be it AP or IB or whatever you may hear others bragging about. Of course it helps if you take exams that make it easy for them to compare you to other students, but if your local high school qualifications show something about where you are at in comparison to other applicants from your country, you should point that out to the committee.</p>
<p>This may be hard to understand if you are used to admissions procedures that are run more mechanically, but think about it this way: the Caltech admissions committee is not accountable to anybody who cares about “fairness” up front. They are accountable to people who care about what <em>comes out</em> of the admissions process. They’ll use any information that you can hand them that can help them predict what kind of student you’re going to be once you get to Pasadena.</p>