school programs in which establishing learning goals, outcome measures, and accountability processes can be especially contentious (see Box 6-1).

In this chapter we organize the discussion of programs for science learning around three distinct age groups: children and youth in after-school and out-of-school programs; adults, including K-12 teachers; and older adults, who have unique developmental capabilities and life-course interests. The emphasis in this chapter on programs for school-age children, and specifically after-school programs, reflects several considerations:

• the committee’s charge to examine the articulation between schools and informal settings;

• the scale and proliferation of out-of-school-time programs;

• the fact that there has been considerable research on this topic, much of it evoking controversy that the committee hopes to illuminate and address;

• the relative paucity of research on programs for adults (including senior citizens); and

• the promise of out-of-school time as a means of engaging a diverse population of children and youth in science (e.g., U.S. Department of Education, 2003).

Out-of-school-time programs have existed for some time, first appearing at the end of the 19th century.¹ Throughout the years, they have changed and adapted to serve different purposes, needs, and concerns, including providing a safe environment, academic enrichment, socialization, acculturation, problem remediation, and play (Halpern, 2002). Diverging goals and the fact that multiple institutions and professional communities share claim to these programs has periodically caused tensions (see Box 6-2).

Today, out-of-school-time programs typically incorporate three blocks of time devoted to (1) homework help and tutoring, (2) enriched learning experiences, and (3) nonacademic activities, such as sports, arts, or play (Noam, Biancarosa, and Dechausay, 2003). Programs are also expanding, in large part due to strong federal and private support. They continue to be supported by various stakeholders with diverse goals for a broad range of student populations.

The bulk of the research on out-of-school-time programs has occurred in the past two decades in conjunction with a rise in governmental and public