DOI
https://doi.org/10.1002/tea.20351

Summary
This study deals with the development of system thinking skills at the elementary school level in the context of the process of water transportation through Earth’s systems.
In order to design a curriculum program that effectively builds upon the Earth Systems approach, authors summarize five system thinking components within the analysis and synthesis levels and relates them to their specific meanings in the context of the hydro-cycle. They also describe how each of these components was implemented within the study unit. Finally, authors list four pedagogical strategies, which together constitute a description of the learning environment that is endorsed as conducive to the development of students’ system thinking.
Authors’ approach focused on the progress students make in systems thinking as a group, and its scope did not allow for the tracking of individual students’ progress as a result of the learning process. Despite the students’ minimal initial system thinking abilities, most of them made significant progress with their ability to analyze the hydrological earth system to its components and processes. As a result, they recognized interconnections between components of a system. Some of the students reached higher system thinking abilities, such as identifying interrelationships among several earth systems and identifying hidden parts of the hydrological system. The direct contact with real phenomena and processes in small scale scenarios enabled these students to create a concrete local water cycle, which could later be expanded into large scale abstract global cycles. The incorporation of outdoor inquiry-based learning with lab inquiry-based activities and knowledge integration assignments contributed to the 4th grade students’ capacity to develop basic system thinking abilities at their young age. This suggests that although system thinking is regarded as a high order thinking skill, it can be developed to a certain extent in elementary school. With a proper long-term curriculum, these abilities can serve as the basis for the development of higher stages of system thinking at the junior–high/middle school level.

Relevance for Complex Systems Knowledge
The paper deals with systems thinking, sustainable development, complex systems, and complexity.
Based on their previous work, authors summarized the eight emergent hierarchic characteristics of system thinking in the context of earth systems. These eight characteristics were then arranged as a hierarchic model of the stages by which system thinking develops in three sequential levels: (a) analysis of system components (characteristic 1); (b) synthesis of system components (characteristics 2 3, 4, 5); and (c) implementation (characteristics 6, 7, 8). Each group of skills (specific level) is used as the basis for the development of the next level’s skills. From the STH model, authors suggest that primary school students, following the learning process, it is possible to master the lower levels of the pyramid (analysis and synthesis): (characteristic 1) the ability to identify the components of a system and processes within the system; (characteristic 2) the ability to identify simple relationships among the system’s components; (characteristic 3) the ability to identify dynamic relationships within the system; (characteristic 4) the ability to organize the systems’ components and processes within a framework of relationships; (characteristic 5) the ability to understand the cyclic nature of systems.
Authors also claim that sustainable development will preserve the capacity of the environment to support life. They consider complex systems as an essential focus for science education, integrating context across several science domains. This recognition of complex systems’ importance, and of the inadequacies of current educational methods in helping students understand them, is a focal point of the extensive research that examine complex systems and complexity theories, as well as on students’ abilities to deal with complex systems of both natural and technological systems.

Point of Strength
The strength of the publication is the presented evidence that appropriate teaching methods help students to advance their system thinking in the context of the water cycle, providing a first step in their holistic understanding of the dynamic and cyclic aspects of larger earth systems.