For some students, online courses are a luxury, a way to get ahead.

For others, they’re a necessity, a path to graduation.

Whatever the reason for online or virtual classes, the number of students taking them in recent years has exploded.

Online courses are mainly offered at middle and high schools. High school students usually take courses that aren’t offered in their schools — college-preparatory courses to get ahead or courses for credit recovery, which allows the students to retake courses they failed or did poorly in.

Nationally, kindergarten through 12th-grade students earned 1.8 million half-credits (the standard credit amount for an online course) in 2010.

The International Association For K-12 Online Learning predicts that number will grow to 5 million half-credits by 2016.

A half-credit is generally earned by a semester-long course if the school is on a traditional seven-period day.

When the school is on a block schedule, as some are in northwest Alabama, those courses earn a full credit.

In Florida, 148,000 students earned 303,000 half-credits through the state’s largest online school, Florida Virtual, during the 2011-12 school year. That number was up from 100 credits 14 years ago.

Such schools provide an alternative education plan for students who struggle in the traditional school setting.

In Alabama, 18,640 students are enrolled in online classes. Those students are primarily accounted for through the state’s ACCESS program, Alabama Connecting Classrooms Educators and Students Statewide. The labs are in high schools around the state and provide students with the opportunity to take the classes they need that aren’t offered in their high schools.

Larry Raines, educational administrator for the ACCESS program at the state Department of Education, said there has been yearly growth in the number of students taking online courses.

“An increase of more than 3,000 students in a year tells us there’s certainly more interest in it and that students and parents are understanding the (relevance) of this mode of education,” Raines said. “We now have middle schools in some parts of the state operating web-based courses. Eighth-graders are now taking the courses. Baldwin County is the most recent to add labs in each of the middle schools.”

Russellville High School has one of the highest number of students taking online courses in the area. Principal Tim Guinn said the number fluctuates each semester, and many of the students taking the classes do so as a result of transferring from another state where requirements to graduate don’t match with Alabama’s.

“The online courses are more difficult because it requires a great deal of self-discipline,” Guinn said. “The students can do the work at school or at home, but they must take all tests at school in the presence of the facilitator. It’s a great thing for those kids who put forth the effort.”

English teacher Greg McCain, an online instructor, attests to the growth in online course participation, saying he has a minimum of 20 per semester. McCain has 47 online students he works with after school hours. They’re from around the state, some taking English credit recovery, others taking English 11, a regular high school level core course.

“I present a curriculum, make the assignments, grade them and provide feedback,” he said. “It’s a great program and helps a lot of kids.”

Northwest Alabama works under the auspices of the Madison City Schools Support Center, one of a few select sites that coordinates ACCESS computer labs and works with lab facilitators and teachers.

Officials with the support center said the majority of Alabama students take regular high school level courses, followed by advanced placement and credit recovery courses.

Sonya Allman, Muscle Shoals High School guidance counselor, said while numbers fluctuate from semester to semester, the courses are valuable for all students.

“Students will most definitely have to be disciplined to do online coursework in college and this is a great introduction to that,” she said. “I encourage it.”

Lisa Singleton-Rickman can be reached at 256-740-5735 or lisa.singleton-rickman@TimesDaily.com.