September 20, 2010

Science Education on the Drawing Board

Post by Ashley Yeager, Duke science writer

Trees don't have to understand how sap rises, but biology students do.

After teaching his students about a tree's internal plumbing a few years ago, biology professor Fred Nijhout asked his Bio 117 students to draw their understanding of these scientific concepts as part of Picturing to Learn, or PtL, a program to research how drawing and visualization can affect science education.

PtL’s mastermind, science photographer and MIT researcher Felice Frankel, created the project after years working with researchers who used drawings to explain to her the phenomena they wanted her to visually capture with her camera.

“As they drew the image to teach me about the science, the process itself seemed to clarify in the mind of the researchers,” she explained during the Visualization Friday Forum on Sept. 17. With this realization, Frankel approached a team of educators and cognitive scientists with the idea of using this in the classroom. All agreed this would be an innovative approach for teaching and learning, and, in turn, the National Science Foundation awarded Frankel and her collaborators a $500,000 grant to test the idea.

Now, four years and 4,000 drawings later, Frankel and her colleagues have evidence to show that “most students get the ideas wrong or partly wrong,” she saiid.

The images were judged based on a rubric that determined whether key points of each concept were accurate or inaccurate in or omitted from the drawing. Frankel cited the 110 depictions of Brownian motion, or particle movement associated with fluid temperature, as an example.

Of the 110, 104 were inaccurate or incomplete, and “these were students from schools like MIT, Harvard and Duke,” Frankel noted.

More surprising were professors’ reactions. “Faculty actually began changing the way they were teaching because they could see that they weren’t communicating,” she said. Anecdotal evidence suggests that the drawings have also become more accurate over the years, as well.

As a result, the PtL researchers are scanning, cataloging and creating an interactive database of images where teachers and professors can go to see the illustrations, filter them by misconception and determine what concepts students, on average, are completely misinterpreting as they learn science. Based on the results, Frankel hopes the PtL database becomes a “self-evaluating teaching tool for educators to keep improving the way they present scientific concepts in their classrooms.” She also plans to publish her findings in a “more academic sense” soon.
 

September 9, 2010

Nanoscale is More Than Meets the Eye

Post by student-blogger Vansh Muttreja:

Although there are vast numbers of nanoparticles around us, it has taken a long time for the ‘nano’ revolution to come to light, Virginia Tech geoscientist Michael F.Hochella Jr., said in a Sept. 9 lecture sponsored by the Center for the Environmental Implications of NanoTechnology (CEINT)

Hochella, the Distinguished Professor at the Department of Geosciences at Virginia Tech, said scientists were able to study tiny atoms and molecules of the order of 10^-8 m in 1914, but it was only around 1980 that the study of nanoparticles was actually made possible.

The major reason for this was because the behavior of nanoparticles is extremely strange as compared to other atoms and molecules. “It was possible to use diffraction and spectroscopy to understand the characteristics of small atoms, but nanoparticles cannot be crystallized and change behavior significantly as you move from the core to the rim,” he said.

Moreover, to deal with particles of this small size, the periodic table had to be modified to include the dimension of size and shape.

It took years to develop several different approaches and extremely powerful electron microscopes that made it possible study the fundamental characteristics and applications of nanoparticles.

There are nanoparticles in abundant quantities that can be utilized for practical applications. “Every day the Mississippi River dumps about 40 million tones of nanoparticles in the Gulf of Mexico,” Hochella said.

As rapid advancements are being made in the field of nanotechnology, it is essential to evaluate the human and the ecological impact of these particles. This has lead to the evolution of nanotoxicology, which aims to understand the adverse effects of nanostructures through the knowledge of the mechanisms and biokinetics of nanomaterials.

Hochella stresses the importance of this field in lieu of the enormous negative impact that materials such as asbestos have had on human health.

It is imperative, he said, to measure and understand the origins of nanoparticles, the geographic distribution, relevant nanochemistry, and the overall influence within the complex physical and chemical framework of Earth systems.

For more information on CEINT- Center for Environmental Implications of NanoTechnology, click here.