We've all been there. A teacher asks a class to answer a simple question with a show of hands. You're not sure of the answer—but lucky for you, the top student was first with her hand up—so there's not much to lose by following suit. The teacher, satisfied by the sea of hands all in agreement, moves on.

It turns out that relying on an age-old practice of a show of hands to check whether students understand what's being taught can be misleading—and can also discourage students from thinking too hard about the answer. 

A new working paper from Levy, Yardley, and Zeckhauser of Harvard University showed the influence of "herding" on students when asked to answer a question. College students' responses to simple questions varied depending on the technique used: hand raising or the use of device that allowed each student to answer a question in real-time without seeing others' responses (often called a "clicker" because students click a button to respond).

For starters, students tended to give much different answers to opinion questions on a sensitive topic depending on whether other students in the class would know (and potentially disapprove) of their answer. 

More concerning, the researchers found that students gave different answers for factual questions with a right and wrong answer depending on the method of responding. 

Specifically, more students got the question right when using hand raising, suggesting that some students follow the lead of the people they assume know the answer. The hand-raising method allows students who mimic others' answers to avoid thinking much about the question and gives teachers a false belief that their students learned the material. When answering with clickers, responses were less likely to be correct—but researchers suspect they were more likely to reflect students' actual understanding of a concept. 

While the old ways are sometimes best, this research suggests that using such devices may be a smart way to bring new technology into the classroom—provided teachers recognize that they are not appropriate for addressing more complicated "why" and "how" questions.

For a closer look at what teacher candidates are learning about asking deep questions, see NCTQ's latest report, Learning About Learning.