Follow Through was the largest and most expensive experimental project in education funded by the U.S. federal government that has ever been conducted. The most extensive evaluation of Follow Through data covers the years 1968–1977; however, the program continued to receive funding from the government until 1995. Follow Through was originally intended to be an extension of the federal Head Start program, which delivered educational, health, and social services to typically disadvantaged preschool children and their families. The function of Follow Through, therefore, was to provide a continuation of these services to students in their early elementary years.

In President Lyndon B. Johnson's 1967 state of the union address, he proposed $120 million for the program, to serve approximately 200,000 children from disadvantaged backgrounds. However, when funding for the project was approved by the United States Congress, a fraction of that amount—merely $15 million—was authorized. This necessitated a change in strategy by the Office of Economic Opportunity (OEO), the government agency charged with oversight of the program Instead, program administrators made the "brilliant decision... (to) convert Follow Through from a service program to a research and development program".

Follow Through planners felt that they were responding to an important challenge in the education of disadvantaged students. It was generally hypothesized that the mere provision of specific supports in the form of federal compensatory programs—such as Head Start and Title I of the Elementary and Secondary Education Act—would result in increased academic achievement for disadvantaged children, if implemented faithfully by committed teachers. However, studies had shown that despite its successes, in general any gains that children made from Head Start (in measures of academic achievement) "faded out" during the first few years of elementary school. It was unclear to policy makers and others if the elementary school experience itself caused this phenomenon, or if specific approaches to instruction within schools were the problem. Follow Through intended to solve the problem by identifying what whole-school approaches to curriculum and instruction worked, and what did not. Subsequently, effective models were to be promulgated by the government as exemplars of innovative and proven methods of raising the academic achievement of historically disadvantaged students.

Sociopolitical context Conceived and implemented in the midst of President Johnson's War on Poverty campaign of the 1960s, Follow Through "came out of larger plan which attempted to lay out the causes and cures of poverty in American society on a systemic basis". In addition to the landmark Elementary and Secondary Education Act of 1965, other initiatives included economic policies designed to maintain levels of high employment and federally subsidized job training specifically targeted at people from disadvantaged backgrounds. These programs were implemented amidst the turbulent era of the 1960s and 1970s; marked by the struggles and eventual enfranchisement of a number of formerly excluded constituencies "including African Americans, feminists, Hispanics, Native Americans, and parents of handicapped children".

Planned variation In typical scientific experiments, treatment and control groups are selected through random assignment. Because Follow Through was an experiment designed to evaluate the efficacy of a number of interventions in local districts, districts chose the interventions they wanted implemented in their schools. This method of selecting a desired intervention among several candidates is called planned variation. One publication refers to it as "random innovation". Planned variation was thought to be advantageous over random assignment because it gave local communities (e.g. community members, parents, administrators, and teachers) an element of local control over the implementation of their program. In fact, Hill believed that programs like Follow Through "can be... permanent sources of advocacy pressure on behalf of the goals and beneficiaries of federal programs".

Goals Follow Through, like Head Start, was enormous in scope, and designed to remedy the fact that "poor children tend to do poorly in school". Despite the cut in funding, it nevertheless served a substantial number of students. At its height, the program would grow to encompass 20 different sponsored interventions and approximately 352,000 Follow Through and comparison children in 178 projects nationwide.

In addition to identifying the most effective instructional practices and disseminating them to schools and districts, it was also hoped that Follow Through would help reduce the number of potentially conflicting federal intervention programs in schools, which was thought by some to be counterproductive and expensive. Moreover, if models could be identified that were effective with needy children, these interventions could be staged in regular education classrooms as well.

Program administration Because Follow Through came into existence because of executive and not legislative action, overall control for the program rested in Johnson's Office of Economic Opportunity (OEO), which spearheaded Johnson's war on poverty policy. A major component of the policy was community involvement. The Community Action Program (CAP) was charged with fulfilling this function through the establishment of local agencies and programs that carried out various federally sponsored initiatives for disadvantaged populations. However, CAP (and, to some extent, OEO) fell into disrepute among legislators and others, because "it resulted in the political mobilization of the poor and the undermining of local government agencies". Follow Through was intended to be an extension of the Head Start community action program. Since Head Start was politically popular, a program associated with Head Start would put the OEO "back in the good graces of Congress". Although Follow Through, like Head Start, was initially intended as a social action program, the decision to transform Follow Through from a social action program to a social experiment was not correspondingly changed in the congressional legislation.

Head Start personnel remained involved in the design and implementation of Follow Through, although it appeared they were working at separate ends from the planning group of the OEO, who viewed Follow Through as an empirical investigation. Much of what occurred during the planning stage—which Egbert describes "as a time of haste and confusion"—was an attempt to satisfy constituencies of both perspectives.

Debates about purpose Due largely to the sociocultural context in which Follow Through was born, planners deliberately structured the program to minimize the involvement of federal officials in the implementation effort. The more Follow Through could be perceived as a locally controlled effort, the better. OEO hoped "idealistically" that Follow Through could satisfy both empirical and social action purposes.

It seems doubtful that any form of experiment could realistically and faithfully serve both aims. According to Hill, true program evaluators should be "technical rather than political or programmatic, and their attitudes skeptical and dispassionate". The planning group of OEO wanted a true empirical investigation that would determine the most effective models. Conversely, CAP and Head Start personnel advising the Follow Through planners viewed it as a social program. Thus, "neither set of constituent groups was fully satisfied with this solution".

Sponsors and models In addition to the planners of Follow Through having conflicting views on the real purpose of the program, the selection of sponsors was equally imprecise. Follow Through sponsors were an eclectic mix of individuals or groups conducting research on instructional methods. Some came from universities, including schools of education. Others were involved in private or grant-based research efforts. The selection method was unclear. According to Watkins, "invitations were apparently extended to any group conducting research on instructional methods".

Some of the sponsors had fairly well developed interventions based on theories of instruction. Others merely had ideas for what might constitute effective interventions. The sponsors also differed widely on the outcomes they expected as a result of their programs. Some sponsors had very specific goals which they believed would lead to very specific outcomes, such as improved literacy skills on measures of reading achievement. Others had more general goals, such as increased self-esteem, or heightened parental involvement in schooling. Most of the programs were in a very early stage of development and had not been extensively (or even moderately) field-tested or piloted. Some programs were so ambiguous that Elmore wrote that "most program developers were simply not clear what their programs would actually look like in a fully operational form". Many sponsors could not explain precisely which aspects of their models would lead to the stated outcome goals of the model.

Despite ambiguities among many of the models (and the minute shades of distinction between some models) the Follow Through literature classified models according to the degree of structure they offered, and where they place emphasis on learning.

The "degree of structure" (e.g. "low", "medium", or "high") offered by a particular model is evidenced by how closely teachers were instructed to adhere to specific procedures, including: ways of arranging the classroom and delivering instruction, the degree of interaction between adults and children, the level of parental involvement, and so forth. Below are brief examples of two models that represent extremes of the spectrum.

Direct Instruction model. Developed by Siegfried Engelmann and Wesley Becker of the University of Oregon, direct instruction is scripted and specifies precisely what the teacher says and what the students' responses should be. Moreover, the program designers carefully sequenced the instruction so that students do not progress to higher-order skills unless they have mastered prerequisite basic skills. There is a high degree of interaction between teachers and students so the teacher may receive continuous feedback about how well the students are doing, and adjusts instruction accordingly. The program makes a specific distinction between on-task and off-task behavior: instruction is arranged so that students are fully engaged in learning (via frequent checking for understanding and praises by the teacher) the majority of the time. According to the program sponsors, anything presumed to be learned by students must first be taught by the teacher.

Bank Street model. The Bank Street model was developed by Elizabeth Gilkerson and Herbert Zimiles of the Bank Street College of Education in New York. In this model, the students themselves direct learning: they select what tasks they wish to engage in, alone or with peers. The teacher arranges the classroom in ways that the sponsors believe will create the conditions for successful learning: various objects and media are available for children to interact with, and the teacher acts as a facilitator, guiding students through activities. According to the program sponsors, students use previously learned knowledge to construct new knowledge. According to the sponsors, given a safe and stable environment, learning is a process that occurs naturally.