Modeling the construction of evidence through prior knowledge and observations from the real world

Evidence is key to many scientific practices including argumentation. For learners engaged in scientific practices, we aim for them to recognize scientific evidence from observations in the natural world. Here, we provide an early depiction of evidence construction, namely how evidence is constructed from one's prior knowledge and one's observations. We illuminate instances of teachers constructing evidence while engaged in a professional development workshop where they are tasked to reconstruct the geological history of a national park. We illustrate four cases, some of which involve the successful construction of evidence and some of which involve embedded challenges with constructing evidence, such as difficulties with background knowledge and individuals "seeing" different information in the same phenomena. This analysis illustrates the role of prior knowledge in scientific practices that rely on evidence construction in field-based complex environments.