Secondary education students follow rigid course guidelines and do not have many options when they choose courses. With some exceptions, postsecondary institutions allow students to study whatever subject they desire.
Postsecondary institutions typically have higher standards than secondary schools; while the grading scale may be the same, earning an "A" is tougher.
At a secondary school, teachers are more accessible but must also act as disciplinarians. At a postsecondary institution, instructors can be remote and expect students to act like adults.
Secondary teachers assign homework at the end of each period. Postsecondary instructors sometimes hand out assignments for the entire semester at the start of the semester, and it's up to students to know what's due for each class.
There are fewer tests in postsecondary courses; some instructors may even replace tests with research papers. Instructors expect students to know material from assigned readings, even if it wasn't discussed in class.
Postsecondary instructors tend to assign more papers. Assigning research papers that are more than 10 pages long is also common.
Secondary teachers will punish non-attendance or unfinished homework assignments. Instructors from postsecondary schools expect students to take control of their learning experience--or fail the course.