This paper builds on earlier studies by the author and another into the understanding of the nature of Earth as a comic body and how this changes as a child develops. It compares five ‘notions’ about the Earth’s nature, ranging from an egocentric view to a more conceptual model. The research was carried out by a university-based researcher in Israel.

Evidence-based suggestions

• Early in teaching, a child should be made aware of the elements of their own notion (naïve and/or egocentric). Only later can and should the teacher confront the child with problems that would place them in a state of cognitive “disequilibrium” that would hopefully be followed by cognitive “accommodations” through notion changes. In this regard, the problems presented to the child in the present study could very easily be adapted for classroom use.
• The interview method should be utilized much more widely in both teaching and research for an assessment of the learning of many other specific science concepts. As was the case with the Earth concept, the interview method would help to increase one’s insight into a child’s development of concepts generally taught in school.

Learners’ ideas

• A student said that the Earth is round and that Columbus was the first one to discover this by his trip around the world, drawing the Earth as round but his other performances indicated that he believed in a flat Earth that constituted the bottom of the cosmos.
• Some students believe that the Earth is a huge ball composed of two hemispheres. The lower part is solid and is made up of soil and rocks. People live on this part. The “upper” hemisphere is not solid. It is made up of “air” or “sky” or “air and sky.”

Study Structure

Aims

The purpose of the study was to answer certain questions concerning the development of the Earth concept raised by an earlier study:

1. Are the “notions” proposed and interpreted in the previous study valid conceptual constructs that would be found again if the study were repeated with a similar population and with somewhat different instruments? If not, what suggestions for refinement and modification can be ascertained?
2. Are the “notions” also valid for upper-grade children to whom the Earth concept is taught formally in class?
3. Is there a common pattern for the development of the concept through the different age levels of the individual child?
4. What implications for teaching can be derived from such a cross-age study?

Evidence collection

Evidence was collected using open-ended interview questions from the previous study (Nussbaum, 1976) modified to a multiple-choice format. Each of the four alternative answers was presented by a drawing. The alternative answers were designed so that each of them would represent one of the five notions being tested. Each of the alternative answers was based on concrete answers offered by children in the previous study and the children were asked to explain their choices.

At the start of each interview, the student was asked to draw a picture that would include the Earth, the sky, the Sun, and the Moon, and some enlarged figures of people standing on the ground. Each individual interview lasted for 20-30 minutes. The child’s responses, choices, and explanations were recorded immediately and were analysed on the same day by his interviewer.

Details of the sample

Pupils were selected from grades 4 to 8 (ages 9 to 14) in a single school in Israel.

Five groups of 48 subjects each coming from grades four to eight constituted the total sample of 240 children. The selection of the groups was as follows:

1. The pupils from each grade level (two parallel classes) were rank-ordered by their teacher into three levels-high, medium, and low achievers.
2. Sixteen pupils were randomly selected from each rank so as to make a total of 48 pupils from each grade level.
3. Each rank group was randomly divided into two equal subgroups.

Combining different rank subgroups together provided two equal halves of the total population. Each half (120 pupils) was interviewed by a different interviewer.