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Lesson plan Grade 8 Art & Music

Coyote Mesa Reservoir Scatter-Plot Infographic Studio

A grade 8 art lesson where students turn eight years of rainfall and reservoir data into a scatter-plot infographic and design its title, labels, and focal point.

Objectives

  1. Students will construct a scatter plot of rainfall against reservoir level and describe the association they see.
  2. Students will identify an outlier and explain how it differs from the pattern of the other points.
  3. Students will design an infographic with a clear title, axis labels, and one highlighted focal point that carries the main message.

Vocabulary

Reservoir
A human-made lake, usually created by a dam, that stores water for later. Reservoirs supply cities and farms and help control floods.

Also: scatter plot, association, outlier, focal point

Teacher overview

An infographic plots data accurately and, through its title, labels, and points of emphasis, also guides what a reader notices first. In this lesson students plot eight years of data from a fictional reservoir, Coyote Mesa Reservoir, comparing each year's rainfall with how full the reservoir ended up. They describe the pattern, find the year that breaks it, and then make design choices, a title, clear axis labels, and one highlighted point, that turn a plain plot into a message a viewer can read in seconds. A common misconception this lesson addresses is that a positive association means every point must fall on one perfect line; students see that a real association can be positive and roughly linear while still having scatter and an outlier.

Procedure

Hook (5 min): Show two versions of the same scatter plot, one with no title or labels and one with a title, labeled axes, and a single bright point. Ask which one tells a story and what the second version added. Keep responses brief.

Direct instruction (12 min): Define a scatter plot as a graph of paired data, one quantity on each axis, used to look for association. Name the vocabulary students will use: positive association (both rise together), negative association (one rises as the other falls), clustering, and outlier (a point that sits apart from the pattern). Then name the design layer: a title states the message, axis labels tell the reader what each direction means, and a focal point, one element made brighter or larger, pulls the eye to the main idea. Model plotting two of the data points on a projected grid so students see how rainfall maps to the x-axis and reservoir level to the y-axis.

Model the read (8 min): Using the projected grid, plot two more points and think aloud: are the points drifting up to the right, and is any point far from the others? Show how you would decide which point to highlight based on the message you want to send.

Independent studio (20 min): Students complete the Student Handout: they plot all eight points, answer the analysis questions, and then make their design decisions. They add a title, label both axes, and color one focal point. The data and the grid are on the handout so the work is self-contained.

Design share (5 min): In groups of four, students lay their infographics side by side and note how different focal-point choices changed the message even though the data were identical.

Closure and formative check (5 min): As an exit ticket, students answer one question on the handout back: "In one sentence, what is the main message of your infographic, and which point did you highlight to send it?" Collect and check that the highlighted point actually supports the stated message; if not, note it for a quick reteach.

Coyote Mesa Reservoir Scatter-Plot Infographic Studio — Grade 8 Art & Music
Name: ____________________________ Date: ______________

Student Handout

Coyote Mesa Reservoir is a fictional reservoir. The table shows, for each year, that year's total rainfall and how full the reservoir was at the end of the year. Plot the data with rainfall on the x-axis (0 to 22 inches) and reservoir level on the y-axis (0 to 100 percent), then answer the questions.

Year Rainfall (inches) Reservoir level (percent full)
2016 14 62
2017 9 41
2018 18 78
2019 11 50
2020 7 33
2021 16 70
2022 12 55
2023 20 85
  1. Plot all eight points. Which year had both the lowest rainfall and the lowest reservoir level?
  2. Which year had both the highest rainfall and the highest reservoir level?
  3. Describe the association between rainfall and reservoir level: positive, negative, or none?
  4. Does the association look roughly linear or clearly nonlinear?
  5. Estimate the rate of change: use the driest year (7 inches, 33 percent) and the wettest year (20 inches, 85 percent) to find about how many percentage points the reservoir rises for each extra inch of rain. Round to the nearest whole number.
  6. A ninth year had 10 inches of rain, but the reservoir ended only 20 percent full. Would this point sit near the others or stand apart as an outlier?
  7. Suggest one real reason the year in item 6 could break the pattern even with ordinary rainfall.
  8. Write the two axis labels you would put on your infographic.
  9. Which single point would you highlight with a bright color to make your main message clear, and why?
  10. Write one sentence that your infographic could use as its headline, based on the pattern in the data.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key
  1. Answer: 2020 (7 inches of rain, 33 percent full). It is the lowest point on both axes and sits at the bottom left of the plot.
  2. Answer: 2023 (20 inches of rain, 85 percent full). It is the highest point on both axes and sits at the top right of the plot.
  3. Answer: Positive association. As rainfall increases, reservoir level tends to increase as well, so the points drift upward to the right.
  4. Answer: Roughly linear. The points rise in a fairly straight band, though they do not fall exactly on one line.
  5. Answer: About 4 percentage points per inch. From (7, 33) to (20, 85), the level rises 52 points over 13 inches, and 52 divided by 13 is 4.
  6. Answer: Outlier. Other years near 10 inches of rain ended between about 40 and 50 percent full, so a year at 10 inches and only 20 percent full sits well below the pattern.
  7. Answer: Any reasonable cause, such as heavy withdrawals for irrigation that year, a very dry year just before it that left the reservoir low to start, or water lost to a leak or release. Accept any explanation that reduces stored water without needing less rain.
  8. Answer: x-axis: yearly rainfall (inches); y-axis: reservoir level (percent full). Accept close wording as long as each axis names its quantity and unit.
  9. Answer: Any point with a stated reason. For a drought warning, highlight 2020 or the item-6 outlier; for a recovery message, highlight 2023. The choice is correct if the highlighted point supports the student's stated message.
  10. Answer: Any single sentence that matches the positive pattern, such as "Wetter years fill Coyote Mesa Reservoir, and dry years leave it low." Accept headlines that state the rainfall-to-level relationship in plain words.

Differentiation

Support

Give students a version of the handout with three of the eight points already plotted and the axes fully labeled, so they can focus on completing the plot and reading the pattern. Provide sentence frames for items 3 and 4.

Extension

Ask students to sketch, by eye, a straight line that best follows the eight points and to use it to predict the reservoir level for a year with 15 inches of rain, then explain how confident they are given the scatter around the line.

ELL supports

Pre-teach "rainfall," "reservoir," and "outlier" with a simple picture of a reservoir filling and emptying. Allow items 3, 4, 6, and 7 to be answered with a labeled arrow or a short phrase, and pair students so the plotting and the wording can be shared.