Kevin Doyle’s classroom at Aragon High School, in San Mateo, Calif., may smell of boiled cabbage, but it’s all for a good cause. The veteran chemistry teacher has cooked up a vat of the purple vegetable. He is using its broth to dye paper coffee filters for a lesson on acids and bases.
When his students arrive at their lab stations, they find stacks of the dried filters and an array of common household products. A lanky tenth grader, wearing a San Francisco Giants T shirt and safety goggles, takes a Q-tip and dips it into a beaker of clear shampoo. When he touches it to the filter paper, it leaves a white dot. So does the hydrogen peroxide. The vinegar and lemon juice leave pink dots. The glass cleaner leaves a green blob. A drop of bleach briefly turns green, and then white. The kids are impressed. They start to paint swirly patterns.
“Make sure you look at the colors dry and wet,” Doyle says, as he walks among his students. “Talk to each other about this; don’t just wait for me to come around. Are these products acidic or alkaline? Can you rank them in ascending pH order? Don’t think you have to make a claim for something you don’t have evidence for.”
Doyle is a highly qualified teacher, with a bachelor’s degree in applied chemistry and a master’s in materials science. He has been working at Aragon High School for 14 years. But it wasn’t until last summer that he gained a deep understanding of how chemistry is best taught.
Doyle and his Aragon colleagues, Leigh-Anne Edklund and Arron Apperson, were among 24 Northern California educators invited to participate in an innovative Stanford professional development program called Chemistry EXperiments and EXperiences for High School Teachers, or ChemEx2 for short. Developed by scholars at the Center to Support Excellence in Teaching (CSET) at the Graduate School of Education, in partnership with Chris Chidsey, associate professor of chemistry, and his colleagues in the Department of Chemistry, the eight-day program showed participants how to build thought-provoking laboratory classes around easy-to-see chemical phenomena. Students encounter these phenomena in the classroom, gather evidence from them, and then use that evidence to build arguments to explain what happened. The idea is to pique students’ curiosity first, and hit them with lectures about abstract theory later.
It sounds simple, but for Doyle it was a revelation. Chemistry textbooks almost always start with atomic structure, as do most high school courses. Yet many 15-year-olds have a hard time picturing molecules and atoms, let alone protons, neutrons and electrons. “Why do we teach theory first?” he wondered. “The giants of chemistry didn’t start that way. They started with, ‘Hey, when I mix this stuff with that stuff, this happens consistently.’ They started with phenomena — things happening.”
Doyle and his colleagues were so impressed by the workshop’s upside-down, “phenomena-first” approach that they went to their principal last fall and asked if they could revamp Aragon High School’s entire chemistry curriculum. “Today,” he said, “we start all of our units by making things happen, and having our students observe. Only then do we slowly add on the layers of understanding.”
Stanford has a long history of engagement with Bay Area chemistry teachers. Graduate students often visit local schools to help with lab demonstrations, and faculty regularly work with teachers on special summer projects in the university’s state-of-the-art labs. The idea behind ChemEx2 was to bring even more chemistry teachers to campus, and have them interact with each other. The program is one in a series of professional development courses in a range of subjects for experienced teachers offered through CSET’s Stanford Summer Teaching Institute, which enrolled more than 300 participants in 2012. Registration just opened for its fifth year of courses at http://cset.stanford.edu/programs/ssti/2013.
ChemEx2 program coordinator Cristina So said that last summer’s program had 75 applicants — nearly three times more than the available slots. One participant drove in every day from Stockton. CSET’s faculty director, education professor Pam Grossman, said she’s not surprised. Most professional development programs for teachers are fairly generic, dealing with topics like classroom management and the needs of particular student populations. “The need for high quality, subject-specific professional development is just enormous,” Grossman said.
At the same time, state standards for chemistry courses have been expanding like bubbles in a hot test tube. “There’s a giant checklist of things teachers have to get through in the lab, and a lot of the people who teach chemistry are biologists or physicists by training,” said Jennifer Schwartz Poehlmann, a Stanford senior chemistry lecturer who helped put the summer program together. “Teachers are saying they don’t have time to teach everything; they don’t have the resources, and some are put into positions where they are not comfortable with all the material. All of these factors are squeezing the fun out of chemistry.”
Her colleague, Chidsey, agreed. “Even in eighth grade physical sciences, the textbooks are so thick, it’s overwhelming,” he lamented. “The burden is put on teachers to try and figure out what’s important and what’s doable. That’s one reason we wanted to get a lot of teachers together on campus, so they could realize they’re not the only ones struggling with this. In ChemEx2, they could ask each other questions, and in the process decide, ‘Of all the things we could teach, which are the most foundational?’
Each of last summer’s ChemEx2 sessions began with a different phenomenon. Like the cabbage juice lab, they used simple materials. One day teachers inflated bags with a variety of gases on tap at Stanford’s Mudd Chemistry Building. On another day, participants used plastic soda bottles, topped with balloons, to illustrate how much carbon dioxide is put out by varying concentrations of baking soda in vinegar.
After each demonstration, the teachers were solicited for their input and encouraged to think about how the phenomenon might be used to teach a variety of concepts in their own classrooms. “They jumped into it with such aplomb,” said Jean Lythcott, a veteran science teacher educator who helped design the sessions. “One of the wonderful pieces of feedback that we got from them was, ‘It’s so fabulous to be a chemistry nerd in a group of chemistry nerds!’ They loved having the freedom to muck around.”
Once the school year started, ChemEx2 participants kept in touch with each other via the program’s website. They gathered on campus again in November and earlier this month for day-long follow-up workshops. In an afternoon brainstorming session on March 9, one teacher solicited advice about handling students who lack the basic math skills necessary for chemistry. Another, determined to incorporate more phenomena into her classes, said she had taped a sheet of paper over her desk listing things to change for next year. She’s not alone. When asked how likely they were to use ChemEx2 material in their classrooms, nearly every teacher in the program responded with a 5 out 5.
Back at Aragon High School, Kevin Doyle and his colleagues are now in their seventh month of the new curriculum. It’s been a lot of work, rethinking classes that they have been teaching for years. But the results should pay off big time when the new Common Core state standardized tests roll around. “Even today, on this little activity with cabbage juice on coffee filters, my students are writing page-long arguments that start with, ‘These must be acids because . . .’” Doyle said proudly. The kids are thinking a lot more now about what they are doing in chemistry class – and that’s a winning formula indeed.
Theresa Johnston, '83, is a Palo Alto freelance writer and frequent contributor to Stanford print and online publications.