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Undergraduate Education

Flipping Chemistry Classrooms

Professors shift lectures online to free up class time for more effective learning activities

by Celia Henry Arnaud
March 25, 2013 | A version of this story appeared in Volume 91, Issue 12

Credit: Regents of U. Minnesota
Cramer helps his computational chemistry students in the computer lab.
Christopher Cramer (standing), a chemistry professor at the University of Minnesota, works with his computational chemistry students during a “flipped” class.
Credit: Regents of U. Minnesota
Cramer helps his computational chemistry students in the computer lab.

Gabriela C. Weaver doesn’t lecture to her general chemistry students—at least not in class. She records short lecture snippets that the students watch online before showing up. During the class period, the students work problems while the Purdue University chemistry professor wanders around the room, observing students, answering their questions, and looking for concepts that are giving them trouble.

Weaver’s strategy is part of a growing trend called inverted instruction or flipped classrooms. In this approach, professors deliver lectures or other class content over the Web via prerecorded videos during the time students would traditionally be doing homework. During the scheduled class time, students work on problems, either alone or in teams.

“The whole idea of flipping the classroom and putting most of the content delivery outside of class time is that it frees up class for other stuff,” says physicist Robert J. Beichner of North Carolina State University. “You can have the students doing things that are more complex, more realistic, because they’ve got an expert there to help them and their teammates to assist them. They get opportunities to practice more in-depth problem solving.”

The trend has gained steam as more and more universities experiment with massive open online courses, or MOOCs. Offered through providers such as Coursera, a company started by Stanford University professors, and edX, a joint venture of Harvard University and Massachusetts Institute of Technology, these free online courses give professors the chance to teach exponentially more students than those who attend their on-campus classes. Those who have already flipped their chemistry classes are using the experience to create such online courses. Others are getting into the business of creating such chemistry MOOCs as a way to produce the materials needed to flip their on-campus classes.

Many flipped classrooms, including Weaver’s, are using an active-learning approach Beichner designed in 1997. Beichner created the approach to fit large classes, where active-learning methods used in smaller classes might be unworkable. In Beichner’s model, students work at tables in teams of three or four.

Weaver has used Beichner’s approach to flip Purdue’s general chemistry class for chemistry majors, which enrolls 50–80 students. She’s found that even when students meet only once every two weeks, learning outcomes benefit.

Currently, the new approach is in its third iteration in second-semester general chemistry. Weaver taught the course in spring 2011, and Mary J. Wirth taught the course in spring 2012, using Weaver’s recorded materials, while Weaver was on maternity leave. For the first two iterations, the American Chemical Society exams were used to normalize student performance between the conventionally taught first semester and the flipped second semester. Both times student performance improved significantly from the first to the second semester.

“I’m convinced that students are getting a better experience by coming to class and doing this high-impact type of experience,” Weaver says. In the future she’s hoping to replicate the experience in the far-larger general chemistry class that other students, such as engineering or premed students, take.

Jeffrey S. Moore, a chemistry professor at the University of Illinois, Urbana-Champaign (UIUC), is taking a similar hybrid approach for his organic chemistry classes, mixing online content delivery with in-class problem solving. “The monologue we deliver is just not an effective way of learning,” he says.

Instead of assigning passages from a textbook for homework, he asks students to watch five or six five-minute webcasts. Students then choose among coming to an in-class problem-solving session, joining the session remotely, or watching a recording later. He can offer so many options because he uses an electronic problem-set package.

“All we ask is that they show up to the exams able to demonstrate that they’ve mastered the ability to solve the kind of problems we’ve been teaching them at the level we expect,” Moore says. To encourage students to join the problem-solving discussion in real time, Moore ends each period with a timed and graded “pressure point” problem that mimics an exam setting. He observes equivalent student performance with most of the options. Students who regularly choose to watch the recorded session are the exception.

Moore’s webcasts are currently being used in a Coursera MOOC on introductory organic chemistry. Moore was slated to be the instructor, but he’s taken a backseat role to UIUC’s Nicholas Llewellyn because he has become interim head of Illinois’ chemistry department.

“In the MOOC, we don’t have this structured discussion period where we’re just working problems,” Moore says. “We’re offering our problems, but the problems are going to be solved with a discussion board as the only means of interacting and asking questions.”

Total official enrollment for the organic MOOC is around 17,400 students, but only about 9,000 watched the first video. Participation continued to drop. The fifth week ended with about 1,000 watching that lesson and about 750 taking the associated quiz. Llewellyn expects the current active students to complete the course.

Llewellyn attributes much of the attrition to unrealistic expectations. “Students expect a MOOC to be accessible not only in terms of being free of charge to all comers but also in terms of being approachable without specialized knowledge or technology,” he says. Teachers need to “clearly manage this expectation in advance by enumerating in detail what skills and knowledge students will need to already have before beginning the course.”

Other professors have joined the rush of MOOCs because they’re interested in creating online materials that they can use to flip their bricks-and-mortar classes.

Michael J. Cima of MIT ran the first MOOC version of his course “Introduction to Solid State Chemistry” (3.091 in MIT parlance) last fall on edX. A second offering started Feb. 5 and is slated to run through June 3. It’s the same course he teaches to MIT freshmen. His course materials include single-concept videos that follow a learning sequence. At the end of the sequence, students answer machine-graded questions about the concepts. Students can also participate in chat rooms on various concepts.

Registrants topped 28,500 for the first iteration, with more than 2,148 finishing with enough mastery to earn a certificate, Cima says. “What these numbers don’t indicate is that more than 15,000 students used the course material through the course,” he says. “We believe they used the material to supplement an existing course they were taking.” More than half were students at other colleges and universities, and almost 10% were high school students.

The student outcomes were equivalent to Cima’s regular class. “I was mostly skeptical of the online assessments,” he says. “But I think I have data to support that online assessment may be better than the current written, timed examinations I do in class.”

Cima is working to figure out how to incorporate the online materials in his MIT class when he teaches it again next fall. “This is going to change how I teach, or at least how I conduct, the 3.091 class here next year,” Cima says. “The students will have online content. They’ll be marching through these sequences, and I will spend more time in my lecture being able to take questions and do problems. It will be a much better class.”

Vicki L. Colvin is another professor using a MOOC to get materials for flipping her on-campus class. When Rice University was looking for professors to do MOOCs, Colvin volunteered. “I’ll have all my videos and can flip my classroom,” she says. “That was my motivation.”

Colvin had been working her way toward flipping her analytical chemistry class for a couple of years. Her students had varying levels of preparation. The course meets twice a week for traditional lectures, but she added an optional weekly problem-solving session, which quickly became the most popular session of the class.

“It was stunning,” she says. “You’d give a lecture, and then you’d show up for the flipped session. It was like you didn’t give the lecture. They learn it when they do it, not when they hear it.”

Colvin next tried to incorporate more problem solving into her regular sessions, switching between short lectures and problem solving. “I realized that wasn’t working so well because it required them to shift between passive and active learning,” she says.

Credit: Vincent Walter
Weaver answers student questions during a flipped class.
Gabriela Weaver teaching Purdue University’s general chemistry class for chemistry majors as a “flipped” class.
Credit: Vincent Walter
Weaver answers student questions during a flipped class.

She decided to plunge into a fully flipped classroom, and the call for MOOCs gave her just the push she needed to create her online materials.

Colvin’s analytical chemistry MOOC starts in May. She admits that her class is unusual for a MOOC, most of which are introductory-level survey courses. Colvin’s class is the same one she teaches to juniors at Rice. More than 9,000 students have already registered for the Coursera version, but Colvin will be satisfied if 100 students finish the course.

“This class isn’t for everybody,” she says. “If you don’t know freshman chemistry, you really can’t take my class.”

Colvin and Cima have both found that converting their traditional lectures into video lectures suitable for MOOCs isn’t as straightforward as they thought.

“I had a full set of lectures from four years of teaching this class,” Colvin says. “It’s a 30-hour-a-week project for me to design my lectures for this new platform.” The challenge is that she needs to break the lectures into five- to 10-minute chunks. “I probably spend 75% of my time on the content and thinking through how to teach it, how to chunk my lectures.” The rest of the time she spends on technical aspects like lighting and sound. She produces her own videos.

In preparation for the MOOC, she’s been using the videos in her Rice class this term. Because this is the first time Colvin has moved all lecture materials online, she worried that her videos might not be up to snuff. She decided not to require students to watch the videos before class, in case she stopped midsemester for some reason.

She’s learned from the experience. “You have to require them to watch the videos beforehand,” she says. “Once I have my stable of videos next year, they’ll be able to watch any video they want, anytime they want.”

Colvin feels that she’s reaching a swath of the class she wasn’t before. “The students I’m reaching with this style are the really motivated but poorly prepared students,” she says.

And even her top students benefit. Like other classes inspired by Beichner’s active-learning approach, Colvin’s is arranged with groups of students at tables. “The top students are leading and helping other students through peer learning,” she says. The students like that role and say that it cements their own understanding of the material.

Even physical chemistry is finding a place in the realm of MOOCs and flipped classrooms. This semester, Christopher J. Cramer, a chemistry professor at the University of Minnesota, Twin Cities, is flipping his computational chemistry class for the first time. In May, he is scheduled to teach a Coursera MOOC on thermodynamics. He hopes to use the MOOC materials to flip Minnesota’s thermodynamics class, which he last taught three years ago. As might be expected for a course that recommends students already have a year each of college chemistry and physics, the preregistration after four weeks was only around 2,000 students, a relatively small number for MOOCs.

Cramer plans to post his computational chemistry videos, which are already publicly available on a Minnesota server, on YouTube when the course ends in May, and he plans to do the same with the videos from his Coursera MOOC. As more such videos become available, flipped classes might be possible at institutions that lack the resources to create such materials themselves. Instructors might start treating the videos like they used to treat textbooks.

“When a college instructor wants to teach a class, he or she hunts around for the best textbook,” Cramer says. “You can imagine that people will start hunting around to find the best video segments. If it involves an entire MOOC, fabulous, but maybe we’ll have little sections that you hunt and click and buy (or get for free).”


Cramer posits one reason that flipped classes help students learn the material: Students willingly watch the videos, whereas they resisted reading the textbook. “We’re tricking the students into spending twice as much time on the material as they would have otherwise,” he says.


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