Semantic Event Model and Its Implication on Situation Detection

Events are at the core of reactive applications, which have become popular in many domains. Contemporary modeling tools lack the capability express the event semantics and relationships to other entities. This research is aimed at providing the system designer a tool to define and describe events and their relationships to other events, object and tasks. It follows the semantic data modeling approach, and applies it to events, by using the classification, aggregation, generalization and association abstractions in the event world. The model employs conditional generalizations that are specific to the event domain, and determine conditions in which an event that is classified to lower level class, is considered as a member of a higher-level event class, for the sake of reaction to the event. The paper describes the event model, its knowledge representation scheme and its properties, and demonstrates these properties through a comprehensive example

Semantic Event Model and its Implication on Situation Detection

Abstract -Events are at the core of reactive applications, which have become popular in many domains. Contemporary modeling tools lack the capability express the event semantics and relationships to other entities. This research is aimed at providing the system designer a tool to define and describe events and their relationships to other events, object and tasks. It follows the semantic data modeling approach, and applies it to events, by using the classification, aggregation, generalization and association abstractions in the event world. The model employs conditional generalizations that are specific to the event domain, and determine conditions in which an event that is classified to lower level class, is considered as a member of a higher-level event class, for the sake of reaction to the event. The paper describes the event model, its knowledge representation scheme and its properties, and demonstrates these properties through a comprehensive example

Development of a Learning Progression for the Formation of the Solar System

This study describes the process of defining a hypothetical learning progression (LP) for astronomy around the big idea of Solar System formation. At the most sophisticated level, students can explain how the formation process led to the current Solar System by considering how the planets formed from the collapse of a rotating cloud of gas and dust. Development of this LP was conducted in 2 phases. First, we interviewed middle school, high school, and college students (N = 44), asking them to describe properties of the current Solar System and to explain how the Solar System was formed. Second, we interviewed 6th-grade students (N = 24) before and after a 15-week astronomy curriculum designed around the big idea. Our analysis provides evidence for potential levels of sophistication within the hypothetical LP, while also revealing common alternative conceptions or areas of limited understanding that could form barriers to progress if not addressed by instruction. For example, many students' understanding of Solar System phenomena was limited by either alternative ideas about gravity or limited application of momentum in their explanations. Few students approached a scientific-level explanation, but their responses revealed possible stepping stones that could be built upon with appropriate instruction