This paper analyzes how the semantics of association relationships in OO conceptual modeling can help to build Navigational Models for Web Applications. The work has been developed in the context of OOWS (a Model-Driven Development Method for building Web Applications). We study some structural and behavioral properties of those al abstractions in order to extract knowledge to be applied in the construction of navigational models. From this study, a set of design rules has been obtained. These rules help the modeler to build navigational models in a systematic way. The results of this work have improved the modeling and code generation processes introduced by OOWS.