Outlines a simple classroom demonstration that illustrates Piagetian conservation. Piagetian conservation refers to the illusion of an increase in mass by changing an object's form. This demonstration, done by forming an ellipse with an extension cord, shows that college students are as susceptible to this effect as are young children. (MJP)

This paper reports the findings of an investigation into the development of the use and understanding of locative and temporal prepositions in 94 children aged from 18 months to 8 years. The research was carried out as part of the Project "Language Development in Pre-School Children," directed by Gordon Wells, at the University of…