Hermione is an introvert, because she is very independant, and thinks a lot inside her head. This, and also the fact that she is happy to spend hour after hour inside the Hogwarts library, without contact with other human beings, which an extrovert would be very reluctant to do.

She is also very Judging, always urging Harry and Ron to arrive to classes on time, and if she was a Perciever, than she woud not arrive to class on time herself, let alone remind other people to.

Hermione also very obviously has the Si cognitive function high on her function order, as she can memorise facts and dates very quickly and easily. Considering that her type so far is IxxJ, the Dominant function would be Xi. As her Si is very strong, then her type would be ISxJ, so her fuctions would be Si, xe, xi, Ne.

Although most people type Hermione as a Thinker, as she is very knowledgeable, she is definately a Feeler. This is because, as a Judger, she would be very reluctant to break the rules, and yet she breaks them year after year, because Harry and Ron need her to. If Hermione was a Thinker, than logic would overpower her need to help her friends. She is also very expressive with her emotions, crying at bullying in the Philosopher''s Stone and indignant and stubborn stand on House Elf rights, all indicate Fe.

She is an introvert, because she is independant, and doesn't share too many secrets with outsiders. Doesn't really like sociallising either.

Annabeth is also iNtuitive, because she just loves information and making connections between places, people and ideas (prophecies).

Definately Thinker, because most of what she does is ruled by logic, a Perciever because she has those rare moments of randomness and impulsiveness (Mount St Helens <3).

I - Not sociable

N - Dreamy

F - Not extremely logical

P - Random

E - Sociable

S - Mechanical

T - Logical

P - Messy and Random