focusing on the six strands of scientific learning introduced earlier and addressing the complexities associated with what people know based on their informal learning experiences.
In both informal and formal learning environments, assessment requires plausible evidence of outcomes and, ideally, is used to support further learning. The following definition reflects current theoretical and design standards among many researchers and practitioners (Huba and Freed, 2000, p. 8):
Assessment is the process of gathering and discussing information from multiple and diverse sources in order to develop a deep understanding of what students know, understand, and can do with their knowledge as a result of their educational experiences; the process culminates when assessment results are used to improve subsequent learning.
Whether assessments have a local and immediate effect on learning activities or are used to justify institutional funding or reform, most experts in assessment agree that the improvement of outcomes should lie at the heart of assessment efforts. Yet assessing learning in ways that are true to this intent often proves difficult, particularly in informal settings. After reviewing some of the practical challenges associated with assessing informal learning, this chapter offers an overview of the types of outcomes that research in informal environments has focused on to date, how these are observed in research, and grouping these outcomes according to the strands of science learning. Appendix B includes discussion of some technical issues related to assessment in informal environments.
Despite general agreement on the importance of collecting more and better data on learning outcomes, the field struggles with theoretical, technical, and practical aspects of measuring learning. For the most part, these difficulties are the same ones confronting the education community more broadly (Shepard, 2000; Delandshere, 2002; Moss, Giard, and Haniford, 2006; Moss, Pullin, Haertel, Gee, and Young, in press; Wilson, 2004; National Research Council, 2001). Many have argued that the diversity of informal learning environments for science learning further contributes to the difficulties of assessment in these settings; they share the view that one of the main challenges is the development of practical, evidence-centered means for assessing learning outcomes of participants across the range of science learning experiences (Allen et al., 2007; Falk and Dierking, 2000; COSMOS Corporation, 1998; Martin, 2004).
For many practitioners and researchers, concerns about the appropriateness of assessment tasks in the context of the setting are a major constraint