Advanced Transactional Models for a New Generation of Educational Modelling Language Engines

E-learning systems have evolved moving from self-contained simple static contents, to the design and execution of learning scenarios described by educational modelling languages (EML) and the integration of Web services. But also carrying with implications such as dealing with long-lived learning activities and finishing activities without accomplishing their learning objectives. Advanced transactional models (ATM) relax some of the basic ACID transaction properties so applications may handle in a reliable way, several types of long-lived activities and compensation activities. An EML execution engine must implement different ATMs in order to provide different levels of transaction support to deal with the diverse types of learning activities.