This strand encompasses the knowledge and skills needed to reason about evidence and to design and analyze investigations. It includes evaluating evidence and constructing and defending arguments based on evidence. The strand also includes recognizing when there is insufficient evidence to draw a conclusion and determining what kind of additional data are needed. Many informal environments provide learners with opportunities to manipulate, test, explore, predict, question, observe, and make sense of the natural and physical world. In fact, most science and nature centers are built around the concept of exploration. Visitors are not given a correct scientific explanation of a natural phenomenon. Rather, they are presented with a phenomenon and then led through a process of asking questions and arriving at their own answers (which may then be verified against current scientific explanations).
The generation and explanation of evidence is at the core of scientific practice; scientists are constantly refining theories and constructing new models based on observations and empirical data. Understanding the connections, similarities, and differences between the ways people evaluate evidence in their daily lives and the practice of science is also part of this strand (e.g., looking at nutrition labels to decide which food items to purchase, understanding the impact of individual and collective decisions related to the environment, diagnosing and addressing personal health issues, diagnosing and testing different possible causes of a broken appliance).
On a small scale, visitors to science centers have an opportunity to engage in scientific reasoning. In these settings, visitors can interact with phenomena, see what happens, and then develop their own explanations for what they just experienced. For example, after experimenting with different objects to see which ones float and which ones sink, visitors can see that shape is just as important a variable as weight in determining buoyancy.
Through trial and error and by asking questions, people can begin to develop a deeper understanding of the world. The process of asking questions and then