Chapter 6, page 81
wanted to find out (1) what alternative conceptions children had and (2) how the conceptions of younger
and older children differed. To address these questions, Vosniadou and Brewer interviewed first graders,
third graders, and fifth graders, asking them a series of questions about the earth’s shape. An important
characteristic of the questions that they asked was that most of the questions could not be answered by
rote memory—simply by repeating a memorized word or phrase. Instead, the questions required students
to reflect on questions that they had probably never thought about before, so that they would have to use
their real ideas about the earth’s shape to answer the questions. Examples of these questions are:
Ɣ Which way do we look to see the earth?
Ɣ Can you draw a picture of the earth? Now on this drawing show me where the stars go..... Now draw
the sky.... Show me where the people live.
Ɣ [The interviewer shows a picture of a house on a flat line.] Here is a picture of a house. This house is
on the earth, isn’t it? How come here (where the house is) the earth is flat, but before you made it
round? [referring to the child’s earlier picture]
Ɣ If you walked for many days in a straight line, where would you end up? ... Would you ever reach the
end of edge of the earth? ... Is there an end or edge to the earth? ... Can you fall off the edge? ...
Where would you end up?.
Ɣ Now tell me what is below the earth?
Some of these questions appeared in the Reflection at the beginning of this chapter.
When Vosniadou and Brewer analyzed the children’s responses to these and other questions, they
found that most children (82%) had coherent conceptions of the earth’s shape. This means that these
children answered all the questions in a way that was consistent with one distinct conception of the earth’s
shape. There were five distinct conceptions (see Figure 6.4). The correct conception, of course, is the
spherical earth conception that appears in Figure 6.4e. The other four conceptions were alternative
conceptions that were very different from the correct conception. These alternative conceptions provide
important insights into how alternative conceptions arise and why they persist despite instruction. We will
first survey the five conceptions, and then we will ask what insights we can gain from understanding these
alternative conceptions.
The flat-earth conception. Children who held the flat-earth conception viewed the earth either as
a flat rectangle or a flat disc (see Figure 6.1a). People all live on the top of the flat surface. Places where
people live, such as the U.S. and China, are all located on the top of this surface. These children think that
there is an edge to the earth, and it is possible to fall off the edge. Other studies have found this to be the
most common conception among first graders and younger children (Brewer, in press; Samarapungavan,
Vosniadou, & Brewer, 1996).
Dual-earth conception. According to the dual-earth conception, there are two earths, the flat earth
(or “ground”) we live on and a round earth in the sky that people do not live on. The dual-earth conception is
the conception expressed by Daryl, the child interviewed by his teacher in the Reflection at the beginning of
this chapter. This transcript shows how another child, a third grader, with this conception answered the
questions about the edge of the earth (Vosniadou & Brewer, 1992, pp. 570-571):