2. Introduction to the problem  
  
"It is often only after selection and installation of the GIS that users, who may not have been consulted in the process of choosing the GIS, then observe that the GIS would perform very quickly, if only somebody knew the commands to type! Unfortunately, this insight comes too late. There is a need for research into developing methods for formally assessing usability so that it can be introduced into the selection process, thus forcing GIS vendors to pay attention to this aspect of their products". (Frank, 1993, 13).   

Frank also stresses, as in the title of his book chapter, that the user interface should not be treated as just another layer of software to be added when the system is more or less functional, rather the interface design should be done first because from the perspective of the nontechnical (typical) GIS user, the interface is the system.