1 The Service Layer is designed to provide high quality data to the application layer. Specifically, the Service Layer aims to provide high accurate results while keeping the cost of the platform low. It also sets the proper price and selects the best workers for the crowdsourcing tasks in order to let the customer benefit more from the crowdsourcing system.
2 The Application Layer is designed for effective collaboration between Crowd and Machine. It provides a set of semantic operators to help requesters decompose high-level jobs into suitable microtasks for the crowd. Meanwhile, it selects the microtasks to be published for crowdsourcing and designs active learning algorithms for accurate inference.