Today's adaptive hypermedia systems are putting more and more emphasis on the intelligence of the system. One of the most important factors in assessing the quality and usability of the system is the level to meet the needs of the user, the learner. So, the learner model, the component that backs up and manages learner information, becomes more important. The learner model is an essential component for adaptive e-learning systems. The term adaptation in e-learning systems involves the selection and manner of presentation of each learning activity as a function that examines the entity of knowledge, skills, and other information given by each subject taught. The chapter aims at studying the functionalities of the learner model in different adaptive hypermedia educational systems in the three stages of developing and managing this model. The authors present in this comparative study a full analysis of the learner model used in 10 major hypermedia to come up with most appropriate method to treat the dynamic aspect of this model.