Chapter 6, page 95
conception that people cannot live on the bottom half of the earth. It is very easy to unintentionally provide
support for students’ alternative conceptions in this way.
Figure 6.5:
Drawing people on the earth
6.5a 6.5b
The teacher could improve her explanation by being clearer and more explicit: “The earth is round like
this globe. People all live on the outside of this sphere. Some people live up here [pointing to Asia and
North America]. Other people live down here [pointing to South American and Australia]. And there are
even some scientists who live way down here [pointing to Antarctica].” Then she draws the picture in
Figure 6.5b to help make these ideas clear. Of course, this explanation would only be a starting point. The
teacher would need to work to help students understand that people living in Australia do not feel
themselves to be standing upside down and that gravity keeps them on the earth. But in beginning with a
clear, unambiguous explanation, the teacher alerts students with the dual-earth and hollow-earth
conceptions that what she is saying is not consistent with their conceptions. This makes it less likely that
they will simply try to assimilate what she is saying into their current conceptions.
Explicitly note common alternative conceptions. Another instructional technique that can promote
conceptual change is to explicitly mention common alternative conceptions (Broughton, Sinatra, &
Reynolds, 2007; Guzzetti, Snyder, Glass, & Gamas, 1993; L. Mason, 2007). By pointing out the
alternative conception to students, she is trying to make sure that they know that the new conceptions are
different from their current ideas. For instance, imagine a teacher teaching fourth graders about the
banking system. She knows that many of her students think that banks are literally place the money
deposited on a shelf, and then return the exact same money to the depositor when the money is withdrawn.
To She begins her lesson in this way:
“Many of you probably think that when you take money to the bank, the banker puts your money on
a shelf, and then gives it back to you when you are ready for it. How many of you think that? ....