Issue Date: April 17, 2017 | Web Date: April 11, 2017
New approaches to undergraduate lab classes
When it comes to developing fresh educational approaches, college and university professors focus on the classroom and often neglect the laboratory. But, at the ACS national meeting, held earlier this month in San Francisco, attendees heard from professors who are working to improve the undergraduate laboratory experience.
Virtual machines sync up classroom and lab
Most instrumentation lab courses use a round-robin rotation approach. In the classroom portion of the course, the professor lectures on a topic—infrared spectroscopy, for example. Meanwhile, in the lab, only one group of students is running an experiment involving an IR spectrometer. The other groups are working with other instruments. At the end of the week’s experiment, the groups rotate instruments, while the professor moves to another topic.
This round-robin approach gives students more time on an instrument in a given week than they would get if everybody did the same experiment on shared instruments. But it also means that for most students, the lab activities are out of sync with the lectures.
Rosina M. Georgiadis, a chemistry professor at Boston University, freed her instrumental methods class from the tyranny of the round robin with “virtual machines.” These computer systems bring an instrument interface into both the classroom and lab for all students at the same time. She described the work in a session sponsored by the Division of Analytical Chemistry.
“In the classroom, 20 students are all on the same interface as if they were standing in front of their own personal instrument,” Georgiadis said. The experience is almost like being in the lab. The only difference is that the software isn’t actually running an instrument.
Students get hands-on experience with the control panel and data analysis before they ever sit in front of the actual instrument. Because the students are better prepared to acquire data with the instrument, they need less time in front of the instrument to collect their data. With their data in hand, students then switch to using virtual machines on their laptops to analyze it, allowing other groups to access the instrument.
As a result, the virtual machines have enabled Georgiadis and lab assistant Kristina Streu to have all their students do the same experiments concurrently and keep their lab experience in sync with the lecture. “You’re lecturing about this one topic that relates directly to the lab experience at hand,” Georgiadis said. “It’s not like four out of five groups are doing unrelated experiments. Everyone is on the same page.”
In a partnership with Agilent Technologies, Georgiadis uses software for six different laboratory instruments that is hosted on Amazon’s cloud services. “Almost every week in this course we were using these virtual machines in some fashion,” she said.
Georgiadis hopes to make the virtual machines available to her colleagues in organic and general chemistry so students in those classes can also become more familiar with using instruments. “I’m working to expand the understanding of instrumentation in the entire undergraduate curriculum and even beyond the chemistry curriculum,” she said.
Instrumentation class heads to the museum
To combat declining enrollment in its instrumentation course, Beloit College’s chemistry department split the class into half-semester modules focused on real-world applications.
In a session at the meeting organized by the Division of Chemical Education, Kevin L. Braun, who teaches the modules, described one that focuses on instrumentation for archaeological inquiry. Students use mass spectrometry, chromatography, and various spectroscopies, especially X-ray fluorescence, to analyze archaeological and anthropological samples.
And the students get to work with real samples. “We’re lucky enough to have access to the Logan Museum of Anthropology,” which is a teaching museum at Beloit, he said. Many of the museum’s more than 200,000 artifacts need to be characterized, and the class is helping make that happen.
For one project, the students screened artifacts for arsenic that had been used as a preservative. “The screening process allows curators and researchers to better understand how to safely work with, analyze, and display these artifacts,” Braun said.
Mounted animals are among the most arsenic-contaminated objects because they often were stuffed with arsenic salts that eventually migrate to the surface. “If you see white powder or crystals around the eyes and feet, most of the time that’s arsenic-based salts,” Braun said. In fact, during the project, the students identified a pair of mounted passenger pigeons that were laced with arsenic.
Because Logan is a research museum, seniors in Beloit’s anthropology or museum studies programs work on research projects at the museum. Braun works with curators and the museum director to identify which student projects could benefit from collaborating with the instrumentation class. “The last time, the student who could benefit the most was actually in the [instrumentation] class,” Braun said.
The new modular approach has helped beef up enrollment in instrumentation classes. The comprehensive instrumentation course that the modules replaced was predominantly taken by seniors.
“We wanted to introduce instrumentation at a much earlier stage,” Braun said. Students can take the modules any time after they’ve completed general chemistry and organic chemistry.
Chemistry majors take at least two out of five modules. But chemistry students aren’t the only ones taking the class. By focusing on topics such as biological and forensic analysis, the modular approach has quadrupled overall participation in instrumentation classes, Braun said.
“I’ve had students from geology, physics, anthropology,” Braun said. “We’ve learned that a lot of these other disciplines require more instrumentation know-how.”
Braun has taught the archaeological module twice, most recently in spring 2016. “We’re hoping to teach it every two to three semesters because I’m alternating it with some of the other modules,” he said.
The class, Braun said, “has been a joy to develop.” It teaches students that there is chemistry in more than just chemistry labs.
Digital badges certify student lab skills
Marcy H. Towns, a professor of chemistry at Purdue University, noticed a problem with her lab courses.
“We had good, solid research evidence that students weren’t learning lab skills,” Towns said. “When we do laboratories in groups, students often off-load the hands-on tasks to the student who displays the most competence.”
So Towns and her colleague Cynthia Harwood came up with benchmarks that ensure all their students acquired the desired skills: digital badges, which are credentials awarded to a student for completing a defined set of tasks. Students earn these badges by filming themselves performing a lab activity according to specific criteria. So far, Towns and Harwood have developed badges for pipetting, reading a burette, and making solutions in a volumetric flask. Towns described the approach in a session at the meeting sponsored by the Division of Chemical Education.
Each badge has a set of instructions that tell the students how to use each piece of equipment. When developing the requirements for a new badge, “you have to figure out what you want to see in the video,” Towns said. “That’s going to be your criteria for assessing whether or not the student knows how to use a piece of equipment correctly.”
The students film themselves and upload the videos using an app called Passport, which was developed at Purdue. Teaching assistants (TAs) assess the students’ performance in the video via comments in the app.
“We’ve developed rubrics that have drastically helped the consistency of grading among the TAs, helping them know what to look for and helping students know what they’re going to be graded on,” said graduate student Sarah Hensiek, who helped develop the digital badges.
Students receive points for successfully completing the tasks. If they use the equipment incorrectly or fail to follow the instructions, their video is rejected. For example, a video might get a thumbs down if a student reads a burette in the wrong direction or doesn’t use the calibration line on a pipette correctly.
“We give them direct feedback so they have an idea of what they did wrong,” Towns said. “They can refilm it using the feedback and resubmit it.”
The digital badges seem to increase the students’ confidence, Harwood said. “After having just done the pipetting badge, the students handle the pipette as if they’ve been doing this for years,” she said.
And the improvements last beyond that one semester. In the second course in the sequence, Towns and Harwood asked the students to “recertify” by earning the pipetting badge again. Towns herself graded about 220 out of 750 videos. “Out of 220 students, 216 of them were approved,” she said. “They know how to do it.”
And for Purdue, there’s been an unexpected benefit from making sure all the students know how to use the equipment. Improper pipetting skills can destroy pipette bulbs when students suck solvent into them. “We were destroying pipette bulbs at a rate of about $3,000 a semester,” Towns said. “We think we’ve saved $8,000 so far in buying pipette bulbs by implementing digital badges.”
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