The course providers featured in this guide, collectively accommodating districts and schools large and small with a variety of courses and delivery models, are Colorado Online Learning, Lakewood, Colo.; Florida Virtual School, Orlando, Fla.; Iowa Online Advanced Placement Academy, Iowa City, Iowa; Johns Hopkins University—Center for Talented Youth, Baltimore; Michigan Virtual High School, Lansing, Mich.; and Virtual High School, Maynard, Mass. Despite several names that include the term "virtual school," all of these providers are supplemental only, that is, they are not diploma- or credit-granting institutions; rather, they work in concert with bricks-andmortar schools, which grant course credit based on the grades provided by the online instructor and, ultimately, grant the high school diploma. Table 1 includes selected variables for each provider. Additional descriptive information about each provider is included in the provider profiles in Part III of this guide.

These highlighted providers were selected from a larger pool of 35 through benchmarking and case study methodologies adapted for the study behind this guide and described in Appendix B. An external advisory group helped guide the development of a research-based conceptual framework (mentioned in that appendix) for analyzing the providers and also informed site-selection criteria. Providers were sought that met five basic criteria:

• Provider and participating school leaders assess students for their readiness to take online courses;

• Provider, school leaders, and parents create a "ladder" for student success in online learning (i.e., ensure adequate student support);

• Courses are designed to meet student needs and are highly engaging;

• Provider has at least two years of performance data; and

• Provider serves students especially in need of greater access, including disadvantaged students and rural students.

All providers were screened using a weighted-criteria matrix; the six providers featured in this publication best met the selection criteria and also represent a range of geographic locations and organizational types (e.g., based in universities or state departments of education, nonprofit).* When online courses are intended to supplement the high school curriculum, course delivery necessarily requires a partnership between the provider and the site-based customer, which, depending on the circumstances and how a provider is set up, can be an individual school or a district operating on behalf of multiple schools. For each of these six providers, several of its education partners (either districts or schools, depending on how the provider works) also were recruited for the study to add the user perspective. These districts and schools were identified by the providers as being active and successful partners that had successfully established online options for their students. They represent a range of settings around the country, from rural high schools to suburban districts to large urban centers. From these varied sites, principals, site coordinators, teachers, parents, and students were interviewed about their experiences with their distance-learning program or online courses.

Table 1. Selected Variables of Highlighted Online Course Providers

To understand what was contributing to success for these providers and a selection of their partner districts or schools, a "snapshot" case study was conducted for each one. Researchers collected data during one-day site visits; conducted interviews in person or by telephone with provider administrators, online instructors, leaders from districts and schools using the providers' online courses, and parents and students; and reviewed online courses and related documentation. This guide synthesizes information from a cross-site analysis of the case studies.

The descriptive research process used to inform this guide yielded some suggested practices— ways to do things that others have found helpful or lessons they have learned. This is not the kind of experimental research that can provide valid causal claims about what works. Readers must judge the merits of any suggestions according to their understanding of the reasoning behind them and how the suggestions may address their local circumstances.