Elementary Teachers' Particle-Based Reasoning Across Contexts: Mental Model Patterns in Phenomenon Explanation and Analogical Modeling

Abstract

Understanding the particulate nature of matter (PNM) requires explaining macroscopic phenomena in terms of unobservable particle-level mechanisms, a challenge for most elementary teachers. This study examined elementary teachers’ expressed mental models of PNM as they explained water’s three states and constructed analogical representations for instruction. Using Merritt and Krajcik’s (2013) framework refined through proposition-level analysis of particle reasoning, six elementary teachers with varied professional backgrounds participated in systematic interviews involving phenomenon explanation and analogical modeling tasks across macroscopic, sub-microscopic, and transfer contexts. Analysis identified three recurring patterns of particle-based reasoning: a Basic Particle Model–Motion, a Basic Particle Model–Distance, and a Quasi-Scientific Model. These categories describe how teachers coordinated particle motion, spacing, and energy rather than representing developmental levels. Teachers' mental models were more consistent during phenomenon explanation than during analogical modeling, indicating task-specific instability when particle understanding had to be transformed into representational form. Analogical modeling functioned as a diagnostically distinct context that exposed coordination difficulties not visible in explanation tasks alone. Differences in cross-task consistency were not explained by professional background alone but appeared related to how teachers evaluated whether analogical representations preserved particle-level relations. These findings refine how elementary teachers’ particle-based reasoning can be characterized and highlight representational and evaluative practices as critical components of modeling competence.