Clickers are a great way to get students thinking deeply about a topic, weighing the arguments and evidence for and against different multiple choice answers. For example, here is a famous biology question that gets students to confront some deeply held misconceptions:
Many people — university instructors included — will often go for A) or B). But trees get their substance from photosynthesis — taking in carbon from carbon-dioxide and converting it into mass. So, the answer is C), and students will often put together a more correct understanding once they get a chance to talk to their neighbors about the question and think more deeply about the process.
But now, most clicker systems offer the ability for students to enter in their own answers, such as numbers and words — called alphanumeric entry – rather than responding to fixed multiple-choice answers. What are the advantages and disadvantages of alphanumeric entry?
First, to fess up, I was always staunchly against alphanumeric entry clickers. I had heard from the early beta testers at my university that such open-responses were a nightmare: Ask students to input the answer to a calculation, and the instructor had to quickly scan over 200 entries to get a sense of the audience. And to make matters worse, “2.0″ is read differently from “2″ or from “two”, making that visual scan nearly impossible.
But I’ve been changing my tune lately, as I’ve talked to instructors with a different view. Much of what I will write about today is taken from a presentation by Matt Evans, of the Department of Physics and Astronomy at the University of Wisconsin at Eu Claire. In the abstract for his talk, Moving from Multiple Choice to Alphanumeric Clickers (American Association of Physics Teachers meeting in Ontario, CA in February) he opines:
Socrates said that the unexamined life is not worth living. I say that unexamined clicker use is not worth using.
So, with that in mind, let’s examine the possible advantages and uses of alphanumeric entry.
Use #1: Ranking
I love asking students to rank-order different choices. But this is cumbersome at best with multiple-choice clickers, leading to horrible answer choices such as BA) 1>2>3, (B) 3>1>2, etc. Matt gave a few examples of excellent ranking tasks:
Instead of asking:
The highest temperature is: (A) 0 F (B) 0 C (C) 50 C (D) 100 F (E) 300K
Instead ask students:
Rank the temperatures from lowest to highest: (A) 0 F (B) 0 C (C) 50 C (D) 100 F (E) 300K
This forces students to consider all answers, rather than only needing some limited information to get the right answer. Matt suggests giving students a visual of the right answer at the end of discussion, since the correct ranking using just the letters (in this case, ABEDC) is hard to parse.
Another nice example that he gave was using graphical analysis:
Use #2: Choose all that are appropriate / More than one right answer
Again, with multiple choice clickers, if you ask students to choose more than one item in a list, the answer choices become quite clunky. Here is an example from Matt’s talk:
And here is the “reformed” version:
One question I like to use in workshops is the following, but you could only do this with alphanumeric entry:
Use #3: Avoid “priming” the right answer
Oftentimes, there is something tricky about a problem or a question, but if you show the correct answer in a list of choices, then students will recognize it as correct. But this doesn’t mean that they could generate the answer on their own. For example, Matt uses this question with his students:
What is the average velocity?
The answer in this case is velocity = displacement / time = -3 m/s. Many students will recognize that the negative sign is important if they see it in a list, but may miss it if they have to generate the answer on their own (or on the final exam).
Which leads us to another use of alphanumeric entry:
Use #4: Numerical Answers
I’d approach this particular use with caution. We’ve found that when you ask students a numerical calculation question, then they turn to their calculators and work individually. But the point of using clickers, especially if you’re using it with Peer Instruction, is to get students engaged and discussing the questions with their classmates. But still, sometimes it can be useful to have students input their own answer rather than giving them a choice of answers.
One item that Matt didn’t cover that I think is another really useful application of alphanumeric entry:
Use #5: Generate answers for multiple choice
One of the questions that instructors ask me a lot is, “where do you find the tempting distractors for multiple choice questions?” While one good answer to that question is to pore through your old student exams and homework for common errors, an even easier way is to give students a question as an open-ended question, and then use common responses for next semester’s multiple-choice version of the question.
Of course, there are drawbacks, as Matt admits:
- Time. It takes longer to cover these in class, both for students to vote, and for the instructor to discuss the answers with the class. So, you can’t do as many open-ended questions in a class as you can multiple choice.
- Harder to grade or assess. This is especially true if you’re giving points for correctness, which is a common practice (but needs to be done sparingly, to not shut down student conversation).
- Harder to get instant feedback from students. A corollary of the above, it’s tougher to scan student responses and get a quick idea of where the majority of the class is.
- More complicated to enter. It’s logistically more challenging for students to input this data, but Matt says that his students don’t seem to mind it.
But overall, I admit, I’d like to try alphanumeric entry questions. They offer a richer opportunity for discussion and student critical thinking, though they’re certainly no magic bullet.