Being an IB student and thus secluded from most of the school, my answer will be generalizing IB students to an extent. Nevertheless, I feel as if IB students are not too unlike the "general population" of Old Mill. Foremost, OMHS students have very close relationships with teachers. Although the reasons are unknown to me, this seems like a universal feature of OMHS students. Often, OMHS students open up to teachers about anything -- academic and personal. Teachers and students tend to almost become friends and begin to share ideas. Students ask teachers for help, and in return teachers ask students for input regarding things like their teaching style. Secondly, OMHS students tend to be mutually beneficial with each other. Like with teachers, fellow students are willing to help each other with anything both inside and outside of the classroom. There is a massive sense of community at Old Mill which embodies itself in the numerous study groups, academic clubs, and extracurricular activities. Lastly, OMHS students take their learning to a deeper level, regardless of the level of the class they may take. It is not uncommon for OMHS students to begin applying concepts they learn in class to their lives and to other classes. OMHS students take the initiative to use their past learning in order to advance their knowledge. I can recall one of my friends almost angrily exclaiming, "kids taking psychology always bring it up in other classes!"
There is no particular "type" of person who should attend Old Mill; students of Old Mill have multitudes of personalities and backgrounds, with the school serving as the basic common ground. However, I believe that a student who is engaged in their learning would fit best at Old Mill. It is necessary for students of this school to be willing and ready to learn; I can say that most students at OMHS meet this criteria to some extent.