As used in this chapter:

(1)  “Correspondence school” means a school that teaches resident and nonresident students by mailing them lessons and exercises toward the achievement of some educational aim which upon completion are returned to the school for grading.

(2)  “Course” means any unit, plan, or program of instruction whether conducted in person, by mail, or by any other method by correspondence schools or home study courses.

(3)  “Home study course” means a course of instruction administered by mail and carried on in the student’s home.