Facilitator’s Guide:
Water Quality and Summary Statistics

Lesson Topics and Standards

  • Water quality
    • Nitrates
    • Nitrites
  • Introduction to Python programming
  • Summary statistics:
    • Measures of center:
      • Mean
      • Median
    • Measures of spread:
      • Standard deviation
      • Range
    • Outliers
  • Data visualization:
    • Boxplots
  • BIO1.LS2.1/ECO.LS2.13/EVSC.LS2.3: Use mathematical and/or computational representations to support explanations of factors that affect the carrying capacity of ecosystems at different scales.
  • SCRE.ETS2.3: Identify the most appropriate scientific instruments and/or computer programs for different experiments and research, and learn to use, care for, and maintain them, gather data, and analyze results.
  • PSCI.PS1.7: Develop, or use, a model to predict or explain a phenomenon by using appropriate indicators.
  • SCRE.ETS3: Applications of Science: Select and use appropriate data tables, graphs, and diagrams to represent data. Use mathematics and computational thinking to look for patterns in data.
  • SCRE.ETS3: Applications of Science: Select and use appropriate statistical procedures (descriptive statistics, t-tests, regression and correlation, chi-square, etc.) to analyze data.
  • A1.S.ID.A.1: Use measures of center to solve real-world and mathematical problems.
  • A1.S.ID.A.3: Interpret differences in shape, center, and spread in the context of the data sets, accounting for possible effects of extreme data points.
  • AGSCIENCE 3.3: Biodiversity: Evaluate the impact of habitat fragmentation, destruction, and other environmental pressures, such as invasive species, overharvesting, pollution, and climate change on local and global biodiversity (genetic, species, and ecosystems.) Distinguish between types of pollution (point and nonpoint sources) and their sources to predict the effects on environmental conditions (e.g., water, soil, and air), animal populations, and plant populations from various kinds of human activity.

Lesson Overview Video Tour


If you would like a more in-depth overview of the lesson, please consult the slides with visible facilitator notes.

Slide Deck for Lesson

Workshop #1 Slides

Student Handout

You can make a copy of the student handout for this lesson.


If you would like to provide students a copy of the slides with spaces for note taking, we have prepared a handout for this purpose.

Lesson Prep

1. Prepare Materials for Nitrates Lab

We suggest creating water samples the for nitrates lab the day before. This will allow the nitrates to fully dissolve in the water.

Materials needed:

  • Miracle-Gro Fertilizer Liquid
  • Dropper/Pipette
  • Small cups for student use (to hold samples for testing)
  • Small sticky notes (we use the 1.875” stickies) grouped into sets of 1 red, 1 green, 1 blue, 1 yellow, etc.
    • Each group will be assigned a color (red, green, blue, yellow, etc.), so the number of stickies in a set will be dictated by the number of groups.
    • Each group will need one multi-colored sticky set per water sample.
  • 1 Sharpie/Poster marker per group
  • Nitrate/Nitrate test strips
  • Masking tape/ sharpies to label cups/samples

Mixing Guide

This plan is written to provide samples for 5 groups with 4 samples each.

For 5 groups × 4 samples = 20 total samples
Fill each cup with 1 cup (8 oz) water, then add liquid fertilizer drops with dropper/pipette:

Normal/Low Range (8 samples) - 0-5 ppm
4 samples: Plain water (0 drops)
4 samples: 1-2 drops per cup

Moderate Range (6 samples) - 8-12 ppm
6 samples: 4-6 drops per cup

Medium-High Range (3 samples) - 15-20 ppm
3 samples: 8-10 drops per cup

Extreme Outliers (3 samples) - 35-50 ppm
2 samples: 20-25 drops per cup (~35-40 ppm)
1 sample: 30+ drops per cup (50 ppm, maxes out strip)

2. Prepare Materials for Boxplot Activity

Materials needed:

  • 1 Post-It Gridded Sticky Page/Group
    • We pre-drew the axis on the page due to time limitations
  • 1 poster marker per group

3. Make Copies: 1 Handout Per Student

  • You will need to make 1 copy per student of the workshop handout. If color-copying is not possible, make sure to have a reference of the color key for the nitrate/nitrite test strips available for each group. Note that the keys vary depending on the brand of test strips you purchase, so you may need to modify the handout to match the specific test strips you are using. Also, the colors are sensitive to lighting and printer setup, so if may be preferrable to have several bottles available for comparison to the orginal key on the bottle itself.

5. Create group tents using colored paper that matches the sticky notes.

6. Create copy of exit ticket for end-of-lesson implementation.

  • We have drafted a three-question exit ticket that aligns with the three major content areas of this lesson (Water Quality, Python, and Statistics). We are providing the Google Form here if you would like to use it or modify it for your own needs.

7. Create copy of the exercise for after-lesson practice.

  • We have also created a Google Colab exercise that you can use with students to practice the concepts covered in this lesson. It is available here.

Lesson Overview & Takeaways

By the end of the lesson, students will be able to:

  • Write and run a basic python script that includes:
    • strings
    • mathematical operators
    • statistics functions
    • print statements
    • lists
  • Explain, at a high level, the role of nitrogen in water quality evaluations
  • Carry out procedures to collect and interpret data concerning nitrate and nirite concentrations from a water quality test
  • Construct boxplots, manually and computationally, to visualize water quality data

Reference Materials

Whole-Class Video Links:
- Water Quality
- Nitrogen Cycle
- Nitrogen as Polutant
- What is Statistics?
- Mean, Median & Mode