The article analyses the importance of the models while methodological resource and abstaction instrument oriented to the acquisition of new knowledge, representation and comprehension of the reality, specially within the context of subject areas whose interest are the phenomena related to information, such as Informatics and Information Science. It examines the arguments that the literature presents on models and modelling, analysing the nature of the models, their basic characeristics, functions and the main types of models. It also analyses the adequacy of the modelling instruments to the development of information systems that considers the whole perceptive view of the users, emphasizing the application of the models to information retrieval systems, mainly those that consider the cognitive aspects. It concludes that more researches on how people face information are extremely needed for the conception of information systems that will have to fulfill the users' needs.
Modelling; Development of information systems; Scientific method; Abstraction; Users' information needs; Information retrieval