, 2006). The proponents of the theory utilizing this method argue that open-ended questions require children productive use of information they already know, unaided by an external representation of the earth (e.g. globe or any other 3-D model). Using this method, superficial (memorization-based) knowledge is eliminated. This enables the experimenters to find out whether children fully understand the information they know (Vosniadou, Skopeliti, & Ikospentaki, 2005). Using the forced-question method, on the other hand, results in less ambiguous answers. When an external 3-D model of the earth accompanies this style, more scientifically correct responses are obtained because the model gives a cue (Panagiotaki, et al., 2006). However, most of the forced questions used by the proponents of the second theory are biased towards a spherical model of the earth (Panagiotaki, et al., 2006). So in the end, the results may not be truly representative of what children do know if the 3-D model they chose is non-spherical (e.g. flattened disk, hemisphere).

While the proponents of the Mental Model Theory agree that the use of the globe or an artifact can facilitate thinking in children, they believe it is not the only legitimate way. Apparently, the introduction of the globe may sometimes confuse children as to their ideas of the nature of the earth. In one study, many children showed inconsistencies in their opinions about the earth after they were presented with a globe, shifting from answering based on their prior knowledge of the earth and then based on the globe as they see it (Vosniadou et al., 2005). However, in that study, the children's previous experiences with the globe weren't taken into fact. It's possible that some of their prior knowledge may include information about the globe that they already know, say from school or at home.

That being said, it may never be...

Even if a child hasn't reached an age where she understands that the earth is in fact a sphere, parents and teachers can lay the groundwork by talking about it in class or going to science exhibits and museums. Callanan et al. (2002) reviewed some strategies for effective parent-child conversations about representational objects, but unfortunately, most are applicable to concrete, rather then abstract concepts. However, they brought into focus the importance of social interaction within which children experience representational objects.
By integrating the social context of the globe-earth link and the theories on children's earth concepts, a likely overall interpretation about children's understanding of the earth could be this: Children can be trained to learn scientifically correct understanding of the earth using the globe as an external model and by giving them fragments of information when opportunities arise, to help them develop their own coherent and non-literal interpretation.

Finally, the lessons learned from the earth-globe research findings can be applied to other abstract concepts in science like atoms, gravity, and evolution. With modern technology and advances in computer-aided design, it is possible to create interesting models of an atom or a visual representation of gravity and evolution in museum or exhibit settings. Children can explore these models while teachers or parents engage them by providing simple information that focus on a particular aspect that the child is interested in. At home, parents and children can look at science picture books or videos and label the objects they see represented on the pages or videotape. In other words, there are various opportunities and many accessible representational objects that can be…