Based on Piaget's theory of logico-mathematical knowledge, 126 students in grades 2-5 were asked 6 questions about elapsed time. The main reason found for difficulty with elapsed time is children's inability to coordinate hierarchical units (hours and minutes). The educational implications drawn are that students must be encouraged to think about…

Agricultural literacy of K-12 students is a national priority for both scientific and agricultural education professional organizations. Development of curricula to address this priority has not been informed by research on what K-12 students understand about the agri-food system. While students' knowledge of food and fiber system facts have been…

In Urmia city, many children learn and speak their first language (either Azari or Kurdish) at home and study all of their courses in Farsi throughout their education. This bilingual quality of education needs to be researched to attain high quality educational practices. The purpose of this study was to examine the effects of bilingualism on…

According to Piaget's theory, maturation of the nervous system is sufficient for the development of formal thought. If this were the case, the job of the educational system would be small indeed. Rather, maturation determines only the totality of possibilities and impossibilities at a given stage. This study investigates whether instructional…

The mean scores of English Language Learners (ELL) and English Only (EO) students in 4th and 5th grade (N = 110), across the teacher-administered Grammar Skills Test, were examined for differences in participants' scores on assessments containing single-step directions and assessments containing multiple-step directions. The results indicated no…

In an attempt to devise a methodology for characterizing children's intuitive theories of drug action, 217 children in Grades 1 to 6 were interviewed about how two substances, alcohol and cocaine, cause behavioral changes in their users. Measures tapped both structure (Piagetian complexity of causal reasoning, coherence, and construction of a…

This document contains the second volume of the proceedings of the 30th Annual Conference of the International Group for the Psychology of Mathematics Education. Conference presentations are centered around the theme "Mathematics at the Centre." This volume features 60 research reports by presenters with last names beginning between Abr…