Grade 8 Task: Clear Water
Investigate what is causing river water to turn cloudy, and test different methods for controlling soil erosion.
Clear Water is a 30-minute interactive computer task in Earth and Space Sciences addressing how human activities can alter Earth’s systems, such as land and waterways. In the task, students investigate what could be causing reduced water clarity in a river that flows into a lake used for fishing and recreational activities. As part of their investigation, students use a tool called a Secchi disk to measure water clarity in the lake and at different locations along the river. Analysis of test results indicates that sediment from soil erosion is the source of river water cloudiness. Students use a stream table simulator to test various erosion control strategies and need to recommend which strategy would be best for controlling soil runoff into the river.
Key findings about student performance on selected questions from this task.
Students were able to apply their Earth and Space Sciences knowledge and scientific inquiry skills to do the following:
33% of students were able to correctly use a scientific instrument to measure and record water clarity.
30% of students were able to design a fair test of erosion control strategies using a simulated stream table.
51% of students correctly identified an erosion-control fence as the most effective strategy for improving water clarity and were able to use evidence from an investigation to explain their choice.
28% of students were able to explain how an erosion-control fence might negatively impact the environment.
Try the Clear Water task yourself and see student performance and scoring guides for all task questions.
Experience this task as the students did
You can experience this task just as students did to understand how they applied their science knowledge and skills to read-world problem-solving scenarios. Select the play button below to start the task. After completing the task you can see the results alongside those of students.