Derek Bruff, assistant director of the Center for Teaching, uses classroom response systems to make his mathematics lectures more interactive for students.
by Kara Furlong
A popular teaching tool in use on campuses across the country, including at Vanderbilt, is helping to reinvent the traditional classroom lecture.
With classroom response systems – or “clickers,” as they’re commonly known – gone are the days of straight lecturing by instructors and note taking by students. Instead, clickers, which look like small remote controls, allow students to become an active component in the lecture process, and allow instructors to gauge – each class period – how well concepts are sinking in.
An instructor using a classroom response system poses multiple-choice questions to his or her students via an overhead or computer projector during the course of a class lecture. The students respond using the handheld clickers, which transmit infrared or radio-frequency signals to a receiver attached to the instructor’s computer. Within seconds, software on the computer reads the responses, compiling them into data that is projected on an overhead screen.
Clickers have been around in some form for about 30 years, initially as keypads hard-wired into the seats of large lecture halls. However, as wireless versions of clickers have become more broadly available in the last 10 years, the technology has taken off both in popularity and variety of use.
Dozens of Vanderbilt faculty are currently teaching with clickers. The technology is in regular use in such departments as chemistry, economics, physics and astronomy, psychology, biomedical engineering, and human and organizational development, as well as at the medical and nursing schools.
“Historically, much of the interest in clickers came from instructors teaching science courses and large lecture classes,” said Derek Bruff, assistant director of the Vanderbilt Center for Teaching, who has done extensive research on the subject. “A lot of it was motivated by a desire to get students more engaged in class, in order to help them learn, but also to assess their understanding in ways that are informative to both student and teacher. As you lead a class discussion with 15 students, you get a sense of what they are struggling with and what they understand, and you can respond appropriately. Once you get beyond 15 or 20 students, it becomes increasingly difficult to organize a class to do those things, and once you hit a hundred or 200 students, there are very few options for having that kind of meaningful interaction.
“Clickers scale up very well - the bigger the class, the more payoff, because clickers can be used to organize a lecture in ways that really get students talking to each other, generating ideas, thinking hard about the content,” Bruff said.
Instructors may pose basic, fact-based questions that serve to keep students on pace with classroom discussion – similar to the “ask the audience” questions on a television game show. Students’ responses are shown in real time, allowing the instructor to gauge their understanding and tailor the lecture accordingly.
Or, instructors may ask questions that generate discussion among the students. Bruff, who is also a lecturer in mathematics, said he prefers this method, sometimes called “peer instruction,” a term popularized by Harvard University physics professor Eric Mazur, whom Bruff met while teaching at Harvard a few years ago. “I pose a question and first have the students vote as individuals. I ask a question that’s right at where the students are having difficulties, and those difficulties are highlighted through the answer choices.
“If we have a distribution where two or three choices are equally popular among the students, then I have them talk about it with their neighbor, and they start discussing and debating and convincing their neighbor that they are right, and in the process, really grapple with the concepts. Then I have them re-vote and see how the answers change. When things are going well, the students will start to converge on the correct answer.
“It’s that type of pedagogy that I think has more impact than the technology itself,” Bruff said. “That pedagogy is difficult to achieve without the technology, particularly in a large classroom.”
Clickers can be integrated into science demonstrations, such as when students are asked to predict an outcome prior to being shown an experiment. Their initial responses both give the instructor a sense of their preconceptions, and serve to engage the students in the experiment – the simple act of pushing a button on the clicker helps to invest them in the outcome.
Clickers can be used to gather demographic or opinion data from a large group of students, such as in a social science class, where the questions being asked don’t necessarily have right or wrong answers. In classes such as economics, psychology or human development, the students may have some direct experience with the topic at hand, and clickers can compile that information quickly and help steer the discussion. The devices also offer anonymity when sticky moral questions – “Have you ever cheated on a test?” for example – are posed to generate discussion.
Bruff said that in preparing a lecture around the use of clickers, “the challenge is that it’s a different type of preparation.”
“You’re saying, ‘What questions can I ask my students that will help me uncover their understanding and help them grapple with the content in meaningful ways?’ That’s a different way of preparing than to say ‘What is the content I’m going to cover today?’“
One trade-off that comes with the format, Bruff pointed out, is that not as much raw material is covered in an average class period. “If you’re going to have your students talking to each other, responding to questions, you’re not going to be able to cover the same amount of material than if you lectured for a straight 50 or 75 minutes.” Bruff said he combats this by having his students read their textbooks before coming to class and giving them online quizzes, graded on effort, to motivate them to prepare in advance.
“I want students in the math courses I teach to develop a conceptual understanding of the content – in addition to being able to use the formulas and do the calculations,” Bruff said. “And I find those are the types of questions I can ask with clickers: multiple-choice questions that surface the missed concepts and illustrate different understandings of them. Often students can pick up the computational techniques they need outside of class as they work through their homework, but the concepts are harder for them to grasp. In-class clicker questions can really help with this.”
One of the best parts, Bruff said, is the immediacy of the technology. “I don’t have to wait until the end of the semester to determine ‘Are they understanding things the way I want them to?’ I leave every class with a pile of data that tells me what the students do and don’t understand.”
Now that the hardware of classroom response systems has matured – transmitters are slim and lightweight, and receivers can plug into the USB port of any laptop – one of the final hurdles lay in the software; faculty new to the technology might have trouble getting started. Bruff is compiling information for a book on the subject. “The book I’m proposing would be designed for faculty who want some practical advice on how to use clickers, what types of questions to ask and how to conduct class in ways that are meaningful when using this technology,” he said. “There’s so much variety in what you can do that I think faculty will find it helpful to see specific examples from their own disciplines.”
Clickers are sold on campus through the Vanderbilt Bookstore, either as individual items or bundled with textbooks, and cost between $20 and $40. Some of Vanderbilt’s schools currently use different systems, though there is discussion for the university to adopt a standardized system, Bruff said, to make the purchase of clickers cost-effective for students, who can reuse them for different classes.
Student reaction to clickers is positive, according to Bruff, whose own students prefer the interaction they provide to simply taking notes. The technology has changed Bruff’s approach in the classroom as well.
“It can completely revolutionize how you teach, and I personally can’t imagine teaching without them at this point,” he said. “To walk into a class and talk for an hour or more without any type of interaction or feedback from my students – I find that very limiting. Teaching with clickers opens the door in so many ways for more active, engaging classes.”
For more information about classroom response systems and resources on campus, visit www.vanderbilt.edu/cft/crs.htm.