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Posted: Aug 31, 2012
Lab course that starts with students' own ideas wins Science magazine prize
(Nanowerk News) Associate Professor Dawn Rickey's first realization that lab classes could be more educational came when she was a teaching assistant for California's cream-of-the-crop chemistry undergrads at UC Berkeley.
"I was really surprised," Rickey says. "They were really good at the mathematics and plugging the information into the equations, but they didn't really understand the lab in terms of what was actually happening."
That realization started Rickey on work to develop a new method of lab instruction. The result, a course module named Exploring Gold Nanoparticles, has been awarded the Science Prize for Inquiry-Based Instruction (IBI).
Science's IBI Prize was developed to showcase outstanding materials, usable in a wide range of schools and settings, for teaching introductory science courses at the college level. The materials must be designed to encourage students' natural curiosity about how the world works, rather than to deliver facts and principles about what scientists have already discovered. Organized as one free-standing "module," the materials should offer real understanding of the nature of science, as well as providing an experience in generating and evaluating scientific evidence. Each month, Science publishes an essay by a recipient of the award, which explains the winning project. The essay about Exploring Gold Nanoparticles, co-authored by Rickey, A. Colin Blair and Ellen R. Fisher, will be published on August 31 ("Discovering Nanoscience").
"We're trying to advance science education," says Bruce Alberts, editor-in-chief of Science. "This competition provides much-needed recognition to innovators in the field whose efforts promise significant benefits for students and for science literacy in general. The publication in Science of an article on each laboratory module will help guide educators around the globe to valuable free resources that might otherwise be missed."
Rickey grew up on the East Coast and was interested in science from an early age, often requesting to go to the Franklin Institute in Philadelphia. A high school class got her excited about chemistry, and at Rutgers University, she had conventional science classes involving lecture and "follow-the-recipe" lab sessions. Because she thought about what was actually occurring in the lab sessions, it never occurred to her that other students were not—until she started her graduate work in chemistry at UC Berkeley.
At Berkeley, her experience as a teaching assistant kindled her interest in science education, and she moved from the chemistry department to a graduate group in science and math education. When she decided that she wanted to focus on undergraduate science education, Rickey, U.C. Professor Angelica Stacy and fellow graduate student Lydia Tien began work on the method behind Exploring Gold Nanoparticles, which they named the MORE Thinking Frame.
One basic premise of MORE is that students start with a model of what they think will happen in a particular lab session before they have started to work with the materials.
"Students are given no information about what to expect," says Melissa McCartney, editorial fellow at Science, "and are instead allowed to conduct experiments designed to allow them to gather evidence to support or refute their initial hypotheses."
As Rickey points out, students and scientists generally start with previous research before embarking on a laboratory exploration, but the MORE Thinking Frame more closely resembles a scientist wandering into a topic of inquiry as though she were the first. "Because of the learning aspect, we want them to start with their own ideas, to activate their prior knowledge," Rickey says, "and then to consider evidence presented in the lab to see if their ideas have changed. The MORE acronym stands for model, observe, reflect, explain."
In the case of Exploring Gold Nanoparticles, the course module chosen to win the IBI prize, students receive a chemical equation for the synthesis of gold nanoparticles. They are asked to describe their understanding of what they think they will observe in the lab and what will happen at the molecular level. They are encouraged to think about what evidence they can collect in the lab to test their models. Students then conduct experiments, synthesizing different sizes of nanoparticles using varying amounts of sodium citrate, for instance, and using laser pointers to collect evidence related to the nature of the reactants and the products.
Using the MORE method, Rickey's research shows and promotes a deep understanding of the material being studied. Even on the students' exams—based on class lecture not lab, and often presenting examples that are slightly different than those explored during the lab part of the class—the MORE method improved students' understanding, transfer of learning from one topic to another, and scores. Students in a control group who were not using MORE did less well.
Rickey's research at Colorado State University, where she is an associate professor of chemistry, delves into why the MORE method improves students' understanding. So far she has found that constructing molecular-level models according to the experimental evidence, reflecting accurately and completely on how one's own ideas about the molecular-level processes changed over the course of the experiments, and identifying evidence to justify changes in those ideas all correlate to deepened understanding. Having the correct idea starting out bears no relationship to acquiring deep understanding.
Meanwhile, the use of gold nanoparticles allows students to understand nanoparticles, which are important to contemporary science and engineering, Rickey says. For example, nanoparticles are used in tumor detection, and the final part of the course module explores the use of gold nanoparticles as optical biosensors. Each laboratory section is given a colloidal gold nanoparticle mixture and synthetic urine samples from two fictitious women (one who is pregnant, and one who is not). The students are asked to design a pregnancy test that distinguishes the urine samples—higher levels of protein, such as the pregnancy hormone human chorionic gonadotropin, bind to the surface of gold nanoparticles, resulting in a color difference—as inexpensively as possible.
Given the success of Exploring Gold Nanoparticles at improving students' overall understanding of the nature of science and scientific models, Rickey says her hope is that winning the IBI Prize and publishing an essay in Science will help her to "share this method of teaching a general chemistry lab, because it has been shown to be more effective at developing students' understanding. I hope people who see the essay will use the module themselves or develop something similar."
Source: American Association for the Advancement of Science