In this report we show the methodology employed to gather and study the material that allow us to know the degree of conception of the sun-earth-moon system, in a group of children from 6 to 11 years of age. This method of investigation is in agreement with those used in similar studies made in Australia by B. Jones, being this paper the first work about the theme, in children of Spanish language. The sample was obtained with children from provincial and national schools in the cities of Villa Carlos Paz and Córdoba (Province of Córdoba) and La Plata (Province of Buenos Aires).