Lesson plan Grade 9 Art & Music
Sable Harbor Desalination Energy: A Grade 9 Infographic Lesson
Grade 9 art students design a one-page infographic comparing desalination and conventional treatment energy, choosing an honest scale, origin, and visual hierarchy.
Objectives
- Students will design an infographic that represents energy data with bars scaled in proportion to their values.
- Students will explain how an honest scale and a zero origin keep a data display from misleading a reader.
- Students will use visual hierarchy so a reader finds the main comparison before the supporting detail.
Vocabulary
- Reverse osmosis
- Reverse osmosis cleans water by pushing it through a membrane with holes so tiny that salt and most other dissolved things cannot fit through. It can even turn seawater into fresh water.
Also: infographic, visual hierarchy, scale, origin, legend
Teacher overview
Sable Harbor is a fictional coastal city that treats its drinking water two ways, through a seawater reverse osmosis plant and through a conventional plant that draws from a river. Seawater desalination pushes water through membranes under high pressure, so it uses roughly two to three times as much energy as conventional treatment and delivery. In this studio lesson, students turn that contrast into a one-page infographic. The design problem is honesty as much as beauty: the most common way a data graphic misleads is a bar whose length does not match its value, so the lesson treats scale, origin, and proportion as design decisions the artist is responsible for.
Procedure
Hook (5 min): Project two quick sketches of the same two-bar chart, one drawn with both bars starting at zero and one drawn with the axis starting partway up so the taller bar looks many times bigger than it is. Ask students which chart is fair and why. Record the word "origin" on the board without defining it yet.
Direct instruction: honest scale and visual hierarchy (12 min): Define infographic, scale, origin, and visual hierarchy. Explain that in a data display the artist chooses a scale (how much length stands for one unit) and an origin (where the measurement starts), and that a bar chart is only fair when every bar starts at the same zero origin and its length is proportional to its value. Then show how hierarchy guides the eye: the largest, boldest, highest element should be the single most important comparison, with labels, source line, and legend deliberately smaller.
Modeled example: choosing a scale for the energy data (10 min): Hand out the data card. For this fictional city, the seawater reverse osmosis plant uses about 4 kWh per 1,000 gallons and the conventional plant uses about 2 kWh per 1,000 gallons. Model choosing a scale of 1 centimeter for every 1 kWh, both bars starting at a shared zero line, which makes the seawater bar 4 centimeters and the conventional bar 2 centimeters. Show a wrong version too, a seawater bar drawn three times the conventional bar, and have students name the error.
Studio work: draft the infographic (20 min): Students draft their own layout on 11x17 paper. Each draft must include a title, the two energy bars drawn to a stated scale from a shared zero origin, a labeled scale or legend, and a one-line source note. Circulate and ask each student to point to their zero line and state their scale in words.
Peer check and exit ticket (8 min): Pair students and have each partner measure the two bars with a ruler and confirm the seawater bar is exactly twice the conventional bar, matching the 4-to-2 ratio in the data. As an exit ticket, each student writes one sentence naming the scale they used and why they started both bars at zero. Collect and scan for a correct statement of scale before dismissal.
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Differentiation
Support
Provide grid paper and a pre-drawn zero baseline so students who struggle with proportion can count squares rather than measure. Offer a partially completed layout with the title box and legend box already placed, so their attention stays on the bars and the scale.
Extension
Ask students to add a third bar for a fictional future plant, choose a value that fits the same scale, and redesign the hierarchy so the new bar does not overpower the original comparison. Have them write a short caption explaining what a reader should conclude and what the graphic deliberately does not claim.
ELL supports
Pre-teach scale, origin, bar, and legend with a labeled diagram and a home-language gloss where possible. Provide a sentence frame for the exit ticket: "My scale is one centimeter for each ___, and I started both bars at zero so the reader can ___." Allow students to annotate their draft with labels instead of full sentences.
Extensions
Invite students to redesign a real utility's published energy or water-use chart that they find confusing, keeping the same data but fixing the scale, origin, and hierarchy. A short written rationale explaining each change turns the redesign into an argument about honest visual communication.