Before completing this activity, your students should have tested a local body of water by macroinvertebrate sampling. They will write lab reports about the procedure they followed and the data they collected. 

Note: If your students are completing this lesson alongside a geoscience or geography lesson, they may turn in a data-based map of the testing site along with their lab report.

Have your students write their lab reports based on these detailed instructions.

In general, the students’ lab reports should meet the following objectives: 

• Describe what you did, following the structure of the scientific method
• Share the data you collected using charts, graphs, and/or maps
• Share and explain the calculations you made based on your data
• Draw conclusions based on your data and calculations 
• Reflect on your overall experience and make plans for what you will do differently the next time you visit the testing site

Have your students read each other’s lab reports. If you had your students do their testing in small groups, make sure that every student reads at least one report associated with each group. As they read, the students should write about the following prompts: 

• Did your classmates encounter problems similar to the ones you faced?
• Compare the data you collected to the data your classmates collected.
• Do you see any major patterns or contradictions? Do the different sets of data tell the same story?
• Does the water quality fluctuate a lot throughout the body of water? In other words, does the problem appear to be more concentrated in some areas than others, or is it pretty evenly spread out? 
• How well does our scientific data match up with our photos/observations? How might the surrounding structures and features in the area be contributing to the problems we found? 
• The next time we visit our testing site, what could we do to make our data more reliable and useful? 
• What mistakes did we make, and how could we correct them? 
• What elements could we add to our study to make our data more meaningful? 
• Which sample spots should we revisit? Should we take samples from any new spots?

Bring the class together for a discussion about the writing prompts above. Take notes as the students talk. At the end of the conversation, make a plan for how you will do things differently during the next round of water quality testing. In addition, start talking about how you might want to share your data.