If you are frustrated with over-enrolled classes or too busy to attend classes on campus, there is another option.

The University of Arizona's Extended University offers independent study through correspondence courses.

"Thousands of students from around the world take UA correspondence classes every year," said Leslie Dykstra, director of the Independent Study Through Correspondence program.

After completing a correspondence course, students receive a letter grade and credit that transfers toward their degree.

"It is a good option for students who work part-time and go to school part-time, and also for students who have failed a course and need to just make up the credits," said Barbara Rossi-Lemoine, testing coordinator for Independent Study.

Lemoine said anyone can take correspondence courses while working, while attending another school or while at home.

"We have a lot of international students as well," Lemoine said.

She said the Extended University offers almost everything that the regular schedule of classes provides and some additional elective courses.

"Before we can offer a class through correspondence we need approval from the department heads themselves," said Lemoine.

She said it is also up to the department heads to choose which faculty or graduate students are eligible to teach these courses.

Once students register for a course, which they can do at any time of the year, they have nine months to complete it.

The program suggests students take 20 days to complete one credit, 40 days for two, and 60 days for three. These students have an instructor they can correspond with and with whom they can discuss their progress with while in the course, Lemoine said.

She said they sometimes take tests through the testing center at the Extended University or, if they are out of town, they can take them with a proctor.

The courses cost $99 per unit.