In this book, the findings of a study on schools within schools are described. The professional research and literature on alternative public education, with a focus on schools within schools, is explored. Based on the research, a list of elements characteristic to and useful for the implementation and perpetuation of optional alternative programs is compiled. Using this list, the evolution of an open alternative in Boston's Parmenter Elementary School is examined. Ten essential elements of Schools Within Schools are defined and four primary factors for successful programs are established: (1) all programs within a school must be viewed as legitimate educational environments; (2) the principal and faculty are prime facilitators of this desired perception; (3) a shared decision-making approach is appropriate to develop and operate an optional alternative; (4) administrators must be aware of the possibility and potential dangers of unintentional segregation by socioeconomic level, race, religion, etc. Recommendations are made for further research. A lengthy bibliography is included. (Author/WI)