There are two types of a learner models:

1. Domain Model This types of models try to associate skills to a particular task and find out the structure of skill domain.

2. Knowledge Model This types of model observe how the student knowledge changes while he/she is practicing. This models are also referred as Knowledge Tracing models. In order KT models to have a good performance it is quintessential for them to apt in describing knowledge state of the student and to be able to correctly classify whether student will answer certain problem correctly.

As it was described in the paper current KT models lack the ability to describe knowledge state or knowledge interaction (interaction of student knowledge state at time t and skill at time t+1). In order to solve these issues the authors create a new model called Knowledge Query Network (KQN)