Advanced Placement

Advanced Placement (website, Wikipedia) is a program created by the College Board in the United States that facilitates students taking college-level courses and getting credit for them while in high school.

Components of the program

Advanced Placement courses

Some schools offer Advanced Placement courses. For each AP course type, the Advanced Placement website provides a guideline as to what topics should be covered in a course on the subject. Schools may offer courses that broadly fit those guidelines, but individual schools and teachers are free to vary the material somewhat.

It is possible to take an Advanced Placement course and then elect not to take the AP test.

Advanced Placement tests

In May of every year, the College Board conducts Advanced Placement tests. Tests are held at schools, so most students take the test at the end in their own school at the end of the AP course. However, people who do not take an AP course are still allowed to take the test, if their school is willing to allow them. In fact, people may take the test at a school they are not enrolled in if the school is willing. In particular, homeschooled students may need to make an arrangement with a local school to allow them to take the AP test at the school.

The Advanced Placement tests have a fee of $89, but various discounts are available.

The syllabus for the tests is consistent with the guidelines for the course, though some skills and topics recommended for coverage in the course may not be suitable for testing and may therefore not be included in the test.

What schools offer Advanced Placement?

A large number of schools in the United States offer some AP classes, but they may offer only a limited subset of APs and may have very few seats for AP classes.
Some international schools in other countries offer AP classes and allow students to take AP tests. These are generally schools that have a tradition of sending students to US colleges. This includes schools in Korea, Thailand, and China, for instance.

Scoring on the Advanced Placement

AP tests are scored on a scale of 1 to 5:

5: Extremely well qualified
4: Well qualified
3: Qualified
2: Possibly qualified
1: No recommendation

College credit policies

Credit is usually offered only for taking the Advanced Placement tests and is contingent on the score obtained in the test. Simply taking an Advanced Placement class does not confer credit. It might still, however, allow people to do well on the University's in-house placement test (if any) and acquire credit through that route.

Subjects where credit is usually offered

AP credit is commonly offered by universities for mathematics (the relevant AP courses are AP Calculus AB and AP Calculus BC). Specifically, universities are willing to recognize AP AB and BC scores in order to allow people to skip out of one or two terms of calculus. However, it should be noted that such credit is usually contingent on getting a good score on the AP test (typically, at least a 4, and for some universities at least a 5 on the AB and 4 on the BC). For more, see Advanced Placement Calculus credit policies and lower division undergraduate mathematics course structure.
AP credits are offered in some science subjects, such as physics and chemistry. People who do not intend to major in a natural sciences subject may be able to use AP credit to avoid having to take college classes in those subjects altogether. Those who do intend to major may be able to place into honors versions of the courses rather than the regular versions. Our general impression is that large introductory science classes (the sort one can place out of with AP credit) are not well-taught at most universities. Therefore, if you can place out of these classes using AP credit, you're probably not missing much).
For humanities subjects, it is rarer for universities to be willing to offer AP credit, because the goal of humanities courses is often to expose people to general ways of thinking and interaction rather than build on a factual base of knowledge. The situation may vary by university, though.

Scores that would confer credit

In principle, scores of 3 or higher on the AP should confer credit.
However, elite colleges generally offer credit only for AP scores of 4 or 5. The amount of credit offered may vary based on the AP score.