This book recognizes several principles:

• Knowledge, practice, and science learning commence early in life, continue throughout the life span, and are inherently cultural.

• Science is a system of acquiring knowledge through systematic observation and experimentation.

• The body of scientific knowledge that has been established is continually being extended, refined, and revised by the community of scientists.

• Science and scientific practice weave together content and process features.

• Effective science education reflects the ways in which scientists actually work.

Science learning involves much more than the acquisition of disciplinary content knowledge and process skills. Like the scientific proficiencies enumerated in Taking Science to School (National Research Council, 2007), science learning can be envisioned as strands of a rope intertwined to produce experiences, environments, and social interactions that provide strong connections to pull people of all ages and backgrounds toward greater scientific understanding, fluency, and expertise. Informal science learning experiences often occur in situations that immediately serve peoples’ interests and prepare them for their future learning in unanticipated ways. Learning experiences in informal settings also grab learners’ attention, provoke emotional responses, and support direct experience with phenomena. In this sense, informal settings occupy an important and unique space in the overarching infrastructure of science learning. At a broad level, informal environments have strengths that are unique and complementary to the strengths of schools.

There are also differences and junctures between informal environments and other venues for science learning, such as K-12 schools, universities, and workplaces. Identifying their respective goals and specific ways in which they do (and do not) intersect can promote thoughtful analysis and coordination of the overarching infrastructure. For example, it is common for schools and science centers to partner with respect to school group visits, teacher education, and summer programs. Despite this overlap, informal environments also have their own distinct mission and mandate. Unlike K-12 schools, they typically do not compel participation. Nor do they have the historical mandate to improve the learning of academic forms of science—especially as measured in terms of standardized achievement indicators—as is increasingly common for formal education. Thus, while informal science learning can be integrated with K-12 science curriculum, the fit is not seamless.

That is why the model of science learning we present here places special emphasis on providing entrée to, and sustained engagement with, science—reflecting the purview of informal learning—while keeping an eye