When I was in school, the surest path to a good grade in science was to memorize everything in sight. Although a boon to my grade point average, this approach did little to expand my worldview. However, when I piloted a more probing unit last year that incorporated the Next Generation Science Standards (NGSS), that's exactly what happened with my 6th graders. I noticed students' perspectives shifting during this problem-based lesson on invasive species. Part of an eight-week unit on sustainable ecosystems created by the Michigan Science Teaching and Assessment Reform project (Mi-STAR), the lesson asked students to weigh-in on Michigan's purple loosestrife problem.
Solving the Purple Loosestrife Problem
Purple loosestrife, an aggressive wetland plant, is common in Michigan. Since my school district borders miles of Lake Superior's shoreline, most students were familiar with its striking magenta spires. What they didn't know was that it chokes out native species, such as cattails, and upends wetland ecosystems. So, I began the lesson by presenting this problem to my students: A fictional nature sanctuary was being overrun by purple loosestrife. What would be the best way to rid the sanctuary of this invasive, exotic species?
There are many ways to control purple loosestrife, but choosing the best method isn't always straightforward. In the real world, science-based decisions don't exist in a vacuum. They are also driven by the needs and values of different, often-competing interest groups. My students became those interest groups. I divided my class into teams of three or four and assigned each team an identity. They would be hikers, government managers, members of a conservation group, and neighbors of the sanctuary. It's important to note that I assigned them to their teams; they did not get to pick their favorite.
Each team received a sheet describing who they represented, along with a decision matrix to complete based on their background. Considering their team's values, they evaluated different ways to eliminate the purple loosestrife—pulling it out by hand, applying herbicide, introducing a beetle that feeds on it—and picked the best solution for their group. Finally, each team presented its preferred solution to the whole class (serving in the role of "town council").
"Acting" Locally
During the town council presentations, I acted as mayor and tried to make the whole experience as authentic as possible. I called the meeting to order with a gavel, gave the students nametags, and addressed them by their last names. For their part, the students were totally immersed in their roles. The managers wore ties and the hiking group arrived carrying backpacks and water bottles. Their presentations were dramatic, silly, and sometimes very passionate. They questioned each other intensely. Even introverts had a chance to shine; because they were pretending to be a character, they were less self-conscious. Finally, as the town council, they voted yea or nay on which method to use to get rid of the purple loosestrife. This was one of my favorite days to be a teacher. Every student was invested and involved.
Thinking Globally
This lesson helped my 6th graders gain a more global perspective in three ways. First, the lesson didn't end once they eradicated purple loosestrife. My class now understands the broader ecological effect of exotic species and realizes they cause problems all over the world. Months after the unit was over, they were still talking about the issue, in class and at home with their parents. Second, by taking on roles representing specific interest groups, they put themselves in another person's shoes, which forced them to consider values other than their own. This skill is invaluable at a time when it seems half the world's woes stem from the inability to respect another person's point of view. Finally, my students were able to practice the critical-thinking and communications skills that are key to good citizenship. They learned to present solid, evidence-based arguments; answer tough questions; and make reasoned decisions.
One of our greatest challenges as educators is to raise a generation that asks thoughtful questions and doesn't reflexively accept any statement simply because it aligns with their own values. This unit seamlessly presents those skills in an unlikely place: a middle school science class. Thanks to Mi-STAR and NGSS curricula, I discovered that my 6th graders were capable of a lot more than I'd given them credit for. Plus, the immersive, authentic problem helped to make school a fun and exciting place.