This middle school unit explores the driving question, "How healthy is our stream for freshwater organisms and how do our actions on land potentially impact the stream and the organisms that live in it?” The project-based learning unit utilizes three-dimensional (3-D) learning envisioned by the Framework for K-12 Science Education (2012) and further articulated through the Next Generation Science Standards (NGSS Lead States, 2013). It builds towards several performance expectations, integrates DCI’s from life and earth science, several crosscutting concepts, and many scientific and engineering practices. Students actively engage in investigation to figure out the health of a stream or another freshwater body as they develop useable understanding of the phenomenon. Throughout the unit, students are engaged in practices such as asking questions, designing and carrying out investigations, analyzing and interpreting data, and developing dynamic computer-based models and constructing scientific explanations. The unit also focuses on students developing useable understanding of several crosscutting concepts -- cause and effect relationships, patterns, stability and change, and systems.
Students collect and analyze pH, temperature, conductivity, dissolved oxygen, and turbidity data at a local creek, stream, river or pond. In this authentic context, students use their real-time data as evidence to create a model and/or to construct a scientific explanation of the water system. Engaging in these practices assists students to systematically analyze data, look for cause and effect relationships and find patterns to determine the quality of the stream for supporting life. Developing models and constructing explanations of complex phenomena, like the water quality of streams, can support students in developing useable understanding of science ideas.