The growth of online learning in PK-12 education has exploded in the past decade. The model has expanded from districts offering a few credit-recovery or enrichment classes to programs that provide a full slate of virtual learning coursework from numerous providers around the globe. 

The online learning industry has evolved so quickly, it's easy to feel confused and overwhelmed. Here are some answers to common questions about virtual learning.

How much online learning is taking place in PK-12 schools in the United States? What are some of the differences across U.S. states?

As early as 2009-10, approximately 2 million K-12 students were enrolled in online courses in the United States, with 74 percent of those students at the high school level, according to the International Association for K-12 Online Learning (iNACOL) Fast Facts. Florida is the state with the largest enrollment of students in online courses. The state's in-district online enrollments are growing while its virtual school enrollments are decreasing due to recent changes in state funding. Enrollment of K-8 students in Florida Virtual School Full Time is on the rise, however, with more than 5,000 attending in 2012-13, according to Keeping Pace.
In 2014, North Carolina will require all students, beginning with the class of 2020, to complete a teacher-led online course prior to graduation. Alabama and Michigan have similar requirements, although students may meet them by participating in fully online courses or online experiences in other courses.

Over the years, credit recovery has served as a major impetus for online coursework. Credit-recovery options enable students who may have previously failed a course or fallen behind on completing required courses to move closer to graduation.
Legislation in Connecticut requires districts with dropout rates of 8 percent or more to provide credit recovery programs, according to Keeping Pace. Connecticut Virtual High School credit recovery classes are designed to enable students to complete a typical year-long curriculum in 15 weeks.

Online options work well for students interested in courses not offered at their local school, students with unique schedules due to athletic training for national or international competitions, and students who are home schooled.

Illinois parent and educator Stephen Curda reports that online schooling provides a consistent learning environment for his daughter, who is living out of her state while acting in various live productions. " "I know a lot of parents of show-biz kids tend to send their kids for this reason," " he said, adding that it reduces the disruptions caused by a rigorous shooting schedule.

What types of models are available?

The contour of online learning involves varied approaches and models across the United States, including fully online schools, charter schools and single district programs.

Cyberschools include statewide multidistrict entities and virtual schools — the latter specifically created through state legislation or a state agency. According to iNACOL, in 2013-14, 29 states and Washington, D.C., had statewide, multidistrict, full-time online schools with more than 300,000 students attending full time.

Virtual schools, school districts and commercial vendors provide programs that range from full-time to single-course offerings for students who attend their local schools. An increasingly popular route is a consortium approach, which links districts and education service agencies to offer local online programs. Multiple states, including Georgia and Utah, maintain statewide clearinghouses to facilitate student access to online learning options from approved providers.

With the advent of the flipped learning model, schools continue to explore and increase blended learning approaches. Fully blended schools are those that deliver a portion of the curriculum online. Many of these schools are charter schools, and only some courses have face-to-face requirements, according to Keeping Pace.

Vendor-produced and delivered curriculum is also growing, says Donna Nicolodi, director of Polk Virtual School in Florida. " "Districts have the option of electing to use their own curriculum or that of a vendor. When using the vendor curriculum, districts also may choose to use the vendor's [instructors] or their own teachers as instructors." "

K12 Inc. works with partner schools in more than half the states, including Idaho and Virginia, to provide curriculum and K12-trained state-certified teachers. In Virginia, it partners with the Virginia Virtual Academy to provide K-5 curriculum. It also has a private online school, the K12 International Academy. Similarly, another vendor, the Connections Academy, partners with the Florida Virtual School Full Time and operates as a charter school in Idaho called INSPIRE — the Idaho Connections Academy. A third vendor, Edgenuity (formerly Education 2020), lists online options that address needs related to core curriculum, credit recovery, and career and technical education for all types of students, including incarcerated youth and special populations.

How are these programs funded?

There are a variety of funding patterns across states, depending on whether students attend full time at a cyberschool or for supplemental learning by taking individual courses. Some states, such as Minnesota, use formulas based on average daily membership. Some states, including Nevada, fund pupils at the same rate as brick-and-mortar schools. And other schools, such as Arizona and Louisiana, provide partial funding.

Here are some examples illustrating the array of options and funding sources:  

• Florida Virtual School (FLVS) offers district franchises of FLVS courses, which are taught by district teachers. Funding is based on successful course completion and performance.
• Georgia Virtual School offers courses for grades 6-12. District and charter online courses are available through Georgia Online Clearinghouse. The school gets partial funding from the state and districts.
• Kentucky uses three approved providers for both individual courses and fully online options. In-district virtual schools are also available. Online options depend on district-level funding. 
• Students in Michigan have access to Michigan Virtual School (MVS), which maintains a catalog of K-12 course options funded by the state; a growing number of cyber charter schools; and the GenNET statewide consortium, which uses multiple providers. Students in grades 5-12 can take two online courses per term. Districts pay most of the cost for courses listed in the statewide catalog, and MVS is funded by state appropriations, course fees and grants.
• Minnesota students can choose courses from multiple providers. State funding follows the student.
• Wisconsin has the Digital Learning Cooperative, which serves middle and high school students. The state has 29 fully online schools. Most of these schools are funded through course fees.
  

What national reports or guidelines are available for administrators, tech coaches and teachers?

The Keeping Pace With K-12 Online & Blended Learning annual report provides comprehensive data on practices and policies in the United States, including detailed state-by-state data. Several publications, such as Classifying K-12 Blended Learning and the Blended Learning Implementation Guide discuss blended learning in more detail. Finally, the 2013 Report Card issued by Digital Learning Now! rates state policies for digital learning on 10 elements, including student access and quality choices.

Arlene Borthwick is associate dean and professor at the National College of Education, National Louis University in Chicago. She served as an ISTE Board member from 2010-14 and received the ISTE Making IT Happen award in 2008. Her research relates to online instruction, personalized learning technologies and school-university collaboration to support preservice candidates' impact on PK-12 student learning.

Randy Hansen is an associate professor and director of the Master's of Instructional Technology Program at University of Maryland University College in Adelphi. His research interests include online teaching and learning, emerging technologies, teacher professional development, and creating active learning environments.