When considering perceptions, the observation scale and resolution are closely related properties. There is consensus in considering resolution as the density of elementary pieces of information in a specified information space. Differently, with the concept of scale, several conceptions compete for a consistent meaning. Scale is typically regarded as way to indicate the degree of detail in which an observation is performed. But surprisingly, there is not a unified definition of scale as a description's property. This paper offers a precise definition of scale, and a method to quantify it as a property associated to the interpretation of a description. To complete the parameters needed to describe the perception of a description, the concepts of scope and resolution are also exposed with an exact meaning. A model describing the recursive process of interpretation, based on evolving steps of scale, scope and resolution, is introduced. The model relies on the conception of observation scale and its association to the selection of symbols. Five experiments illustrate the application of these concepts, showing that resolution, scale and scope integrate the set of properties to define any point of view from which an observation is performed and interpreted.