Picture a jeweler at work. Magnifier in hand, he examines a stone, studying the way light dances off it. He’s trying to determine whether it’s a diamond or merely cut glass, of engagement-ring quality or thrift-store inferiority. How, the science teacher asks his class, can he tell?
Maybe the jeweler can tell by the stone’s weight, one student suggests. Or its size, another says.
But let’s assume that stone and another are of equal weight and size, the teacher responds. What can the jeweler determine from their appearance when they’re held to the light?
“A diamond gives off a rainbow when cut glass doesn’t,” a youth says.
This recognition, even if it comes gradually, is what 9th grade physics teacher Matthew Anthes-Washburn is looking for. The discussion is the first step in trying to produce a successful science laboratory—a staple of the high school classroom experience.
Today’s lesson is on refraction, the way light bends as it passes from one material to another. Mr. Anthes-Washburn is trying to use students’ common experiences to introduce them to science, before he explains more specific vocabulary and underlying concepts. The sparkle of a diamond, he hopes, is one such experience.
After that introduction, the teacher at West Roxbury Education Complex in Boston has students break into small groups and use a simple set of tools—clear acrylic blocks, glass rods, and miniature laser pointers—to trace the path of light beams with graphing paper. They record their observations and answer written questions on their laptop computers.
Every school day, teachers like Mr. Anthes-Washburn seek to build students’ scientific understanding through labs in biology, chemistry, and physics. It’s not easy. A national study released in 2005 concluded that most high school students are not exposed to high-quality science labs.
Too often, it found, teachers and curricular materials do not connect lab work with the rest of science content presented in class. Labs are too focused on procedure, leaving students unsure about what they’re supposed to learn, rather than improving their scientific thinking, according to the study, which was conducted by the National Research Council.
Mr. Anthes-Washburn is trying to overcome those obstacles by making his labs a primary learning tool rather than a secondary amenity. He and other teachers using the same curriculum say that it relies on an “ABC” approach—activity before content. 69ý first take part in hands-on activities so that the science content presented later will have greater meaning.
That model is essentially the reverse of how labs are used in many science classrooms, where teachers lead students through lectures and content upfront, before sending them to lab activities. Mr. Anthes-Washburn says his goal, by contrast, is to promote inquiry—a broad term that generally means having students gain scientific knowledge through the activities and processes used by scientists, such as observation, investigation, and the interpretation of data.
“It’s a truer model of scientific thinking,” Mr. Anthes-Washburn says of the approach. “In the field of science, if you’re in a lab, you don’t have a fixed outcome” in which researchers are presented with the correct answers at the outset. He wants to gradually build students’ ability to conduct science over the course of a year.
Teachers and scientists have long recognized the importance of labs in science lessons. By the mid-1800s, educators began to see a need to teach high school and college students more about the methods and procedures used by scientists, as opposed to simply having them read about that work, or hear it described by teachers, the NRC report notes.
The National Research Council found that most students are not exposed to effective labs. The NRC study cited a number of reasons for labs’ shortcomings.
• Poor school facilities and organization.
Many schools lack the space for labs; others have overly rigid schedules that do not allow students to participate often enough for labs to have a positive impact on learning.
• Weak teacher preparation.
Teacher colleges and other universities provide educators with little training on conducting effective labs; professional-development activities for veteran teachers are limited in quality and availability.
• Poor design.
Many labs are not designed with clear learning goals in mind, and are disconnected from the flow of science lessons. 69ý are not encouraged to discuss their preconceptions about scientific topics before, during, and after labs.
• Cluttered state standards.
Influential academic documents encourage schools to cover long lists of science topics by grade and offer little guidance for including labs in the flow of classes.
• Little representation on state tests.
Science assessments given by states do not gauge student skills in using labs—which contributes to the lack of attention they receive in schools.
• Scarce evidence of what works.
Little research exists on what types of labs are most effective; scientists and researchers even disagree on how to define a science lab.
SOURCE: National Research Council
Today, high school students on average take part in one lab activity per week in science class, research shows. Yet disagreements persist on the most effective way to structure labs and how to balance them with straightforward, teacher-led presentations. Little definitive research is available on what works best, experts say.
“Everyone will tell you that labs are essential,” said David P. Licata, a chemistry teacher at Pacifica Heights High School, in Garden Grove, Calif., who served on the NRC committee. “But after that, there are all these different things that could come out of lab experience, so [finding a consensus] is difficult.”
Nonetheless, the committee of scientists, teachers, and academic researchers identified a number of effective strategies for organizing labs. Those steps include having teachers clearly spell out the purpose of an activity for students; explicitly linking those activities to the content presented in class; and prodding students to discuss the overall scientific meaning of activities, rather than simply the procedures they followed.
Boston’s public schools have attempted to place a greater emphasis on lab work across many grades in recent years, according to Marilyn Decker, a senior program director for science for the 58,000-student district. One step in that direction came through its adoption four years ago of the Active Physics curriculum, which Mr. Anthes-Washburn and other teachers are using.
It places a heavy emphasis on labs, while introducing students to physics in 9th grade, in contrast to the more traditional approach of having them take it as juniors or seniors. The district greatly increased professional development in an effort to improve teachers’ use of labs and overall skills, Ms. Decker said.
Arthur Eisenkraft, who helped write the Active Physics curriculum, said that in too many schools, labs are held well before or after—sometimes weeks after—a teacher presents a lesson because of either instructional reasons or scheduling conflicts. Active Physics is aimed at ending that disconnect, said Mr. Eisenkraft, a professor of science education at the University of Massachusetts Boston and a former president of the National Science Teachers Association.
“The lab is an integral part of the class,” he said. “It’s not an added-on part.”
Active Physics drew criticism recently from parents in the San Diego school system who complained that teaching physics in 9th grade amounted to watering down the subject. Last year, the district dropped a requirement that physics be taught at that grade level, and decided to give individual schools more freedom to set grade-by-grade course schedules.
Supporters of Active Physics maintain that it provides all students with the opportunity to take a science subject traditionally reserved for elite students, and gives them a better foundation for studies in chemistry and biology. Boston has seen the number of students—particularly minority students—taking Advanced Placement science courses greatly increase since it began using the curriculum, which Ms. Decker sees as evidence of their becoming more comfortable with demanding academic material.
Paul R. Gross, a professor emeritus of life sciences at the University of Virginia, said curricular models that put a heavy emphasis on labs can work—as long as those activities do not become an excuse for students to simply “do something easier” than learning challenging science content. Mr. Gross led a 2005 study by the Thomas B. Fordham Foundation that was critical of states’ emphasis on “inquiry-based” instruction. Labs can boost students’ enthusiasm for science, he said—but teachers should provide firm guidance and high expectations throughout those activities.
“You need to teach science,” Mr. Gross said. “The teacher is not [just a] facilitator. The teacher is a resource and an example.”
Mr. Anthes-Washburn, who is in his sixth year of teaching, is trying to offer direction to a diverse group of students, many of them from disadvantaged backgrounds.
West Roxbury Education Complex was broken up a year ago into four smaller high schools, and he works at the Parkway Academy of Technology and Health, which focuses on integrating technology into other academic areas. Seventy-eight percent of PATH’s student population is eligible for free or reduced-price lunches. At the 10th grade level, just 52 percent of students achieved at least a “proficient” score on Massachusetts’ English/language arts assessment in 2006, and only 55 percent reached that mark in math. Those scores lagged behind state averages.
Scott Bartholomew, a 9th grade science teacher who works down the hall from Mr. Anthes-Washburn, says many of his students struggle with basic scientific vocabulary—terms such as “acceleration” and “velocity.” While his students resist reading and writing exercises, they are more enthusiastic about labs, which he uses to prepare them for unfamiliar terms.
“It gives them an access point” to science, Mr. Bartholomew says. “The way I learned science was through a book. That was my access point.” Labs can “draw kids in,” he says. “If they’re not interested in what you’re telling them, they’ll just tune you out.”
The attempt to use labs to build content knowledge was on display in Mr. Anthes-Washburn’s class one recent day. 69ý leave their desks and regroup at small tables in threes and fours. With hand-held laser pointers, they direct beams of red light at pencil-length glass rods, with acrylic blocks behind them. The laser ray bends one direction, then another. The students then record their observations.
“That’s the angle of incidence,” the teacher says, pointing to a spot on one group’s graph. The class will review the term later, along with other definitions.
Kostandina Bullari, 15, says labs have helped her connect science to everyday activity. She took part in what she considers her favorite lab a few weeks before, when students constructed miniature houses and tried to insulate them, to study the movement of hot and cold air.
“When we do projects from the book, it’s work,” Ms. Bullari says, “but I like the experiments.”
Researchers have identified a few strategies for creating effective hands-on activities that will improve students’ science learning.
• Clearly stated purposes.
69ý must understand the explicit goals of a lab in order to understand the science behind it and carry it out effectively.
• Effective sequence.
Labs should be connected to what students learned before—and after— that particular hands-on activity. They should be integrated into instruction, rather than presented as isolated events.
• Blending of content and process.
In conducting labs, teachers should emphasize both scientific content in their classes and the processes used by scientists in their work.
• Discussion and reflection.
69ý in a lab should be encouraged to discuss and reflect on those activities. They should be asked to develop explanations and make sense of patterns in data—-not just confirm ideas that a teacher has presented to them.
SOURCE: National Research Council
For Mr. Anthes-Washburn, the hard work comes in keeping an entire class on task, two weeks before his school’s winter break. Some groups won’t start the activity until the teacher prods them. If he isn’t watching, students will begin talking, or doodling on their laptops. When one comes back from the bathroom, another asks for permission to go. One young man who refuses to work is asked to leave class so Mr. Anthes-Washburn can talk to him in the hallway.
Coping with the steady disruptions isn’t easy, the teacher acknowledges after class. But despite the ruckus, students who participated have been given an important foundation that will make the next day’s science lesson seem a little less abstract, he predicts.
“I still win,” Mr. Anthes-Washburn says. “Tomorrow, when I teach about refraction, they’ll have had that physical experience. … My goal is to get everybody to have contact with it. If everyone can get the big idea, that’s a success.”
