As recently as 2008, a review of clickers in Chemistry Education Research and Practice had difficulty finding reports of their use in chemistry lecture rooms. In the intervening years, the increase in usage has been nothing short of meteoric. It’s interesting to survey the recent literature to consider how clickers are used in chemistry.
The first category is those who use clickers in a simple check of the class’ understanding of a topic – do they know x? King (JCE, 2011, doi: 10.1021/ed1004799) describes the use of clickers to allow a class to identify the ‘muddiest point’, with the most common cause of difficulty being the subject of a review in the following lecture.
Initiate class/peer discussion
The second type of usage is to use clickers to gauge opinion from the class, often on a misconception, and use the initial class responses as a basis for discussion, with possible reassessment. Wagner (JCE, 2009, 86(11), 1300) describes the use of clickers in this manner, for example in asking students: which of the following substances has the ID(50) value? [aspirin; DDT; nicotine; caffeine; ethanol]; and initiating a subsequent class discussion based on the student responses. Mazur’s Peer Instruction is based on this approach.
Ruder and Straumanis have a very nice paper (JCE, 2009, 86(12), 1392) on using digit response function in some clicker handsets so that students may input a sequence. Two examples illustrate the concept. in the first, students have to select which two precursors from two lists of reagents (in this example Michael donors and acceptors) they would choose in order to prepare a desired product. In their second example, students are asked to select the reagents they would add, in the correct sequence, to produce a desired product. These questions offer two advantages; they allow for a much larger set of possible answers and so minimise a lucky guess and they require students not only to know an answer, but to consider that answer in the context of a total problem. Clickers which do not allow numerical answers can still consider this approach – several more incorrect answers can be easily generated, and if clever, common wrong answers can be included. In fact, the authors say that they only show the responses to the top few most common incorrect answers.
This approach is also used by these authors to test students on curly arrow mechanisms – carbon atoms in a diagram are numbered, and students can describe their understanding of the mechanism by entering multiple-digit responses to represent a mechanism. It’s clever, but some of the very extensive models described seem a bit elaborate to expect students to be able to “code” their curly arrow mechanism into numbers. However, it shows how far the technology could be pushed. A similar approach using numbered carbons on complex organic structures as a basis for numerical entry is described by Flynn in her work on teaching retrosynthesic analysis (JCE, 2011, doi: 0.1021/ed200143k).
What and why?
My own use of clickers follows Treagust’s work (e.g. CERP, 2007, 8 (3), 293-307), where he asks students two-stage multiple choice questions. The first is a simple response, and the second is asking students to select why they chose that response. This work by Treagust is very clever, as it allows students who may know or guess the correct answer to really challenge themselves on their understanding of why they know what they know. The wrong answers in Treagust’s work are developed from literature reports of misconceptions. He has been very generous in sharing examples of these in the past.
In the lab
My colleagues Barry Ryan and Julie Dunne completed some work using clickers to assess pre-and post-lab activities. You can find out more about that here.
Do you use clickers? If so, I’d be interested to hear how in order to compile a “Chemist’s User’s Guide”.