From what was stated before, it must be clear that the validity concept is a very important one. The proposed architecture for the User Interaction Module (MIU), generated by the GAMA-X, will not follow the strict separation between semantic component (Application Model), syntactic component (Dialogue Controller), and lexical component (Presentation Model) proposed by the Seeheim Model [2]; although we have an Application Model, a Dialogue Controller, and a Presentation Model, they will have slightly different tasks from those proposed in the Seeheim model, because the sematics of the application has to be present in all three.
Being obvious that the application data representation is unacceptabel for the user to use and also, since at start it is unknown
, it can not be used by the Dialogue Controller, we have to have different representations (actually three) for each value within the interactive system.
The application data representation, which we will call sematic representation, is of the responsability of the computational layer (smdata); in the Dialogue Controller we use the XMetoo data representation, and we call it syntactic representation (stdata); the data representation in the presentation layer will be specified in the Presentation Model, being one of a set of possible representations, and is the lexical representation (lxdata).
We have then to make the translation between the diferent representations, so that a value in the application might be sent to the presentation and vice versa. The smdata/stdata translation is made by the Application Model, since the semantic representation depends on the application. The translation functions will be the reification and retrive functions derived from the reification process. The lxdata/stdata translation will be done by the Presentation Model. In this way, all three components use the stdata representation to communicate with each other.
As the XMetoo representation is used as the syntactic representation, each component will have a Xmetoo server so that it can manipulate the data. In the Application Model this server will also execute the prototypes ("stubs") of the operations not yet implemented. Thus, in an initial stage all operations execution requests will be delt with by the XMetoo server. With the progressive reification of the application layer more and more requests will start being passed to the application. Eventually all the operations will be implemented by the computational layer.
When all the perations are present in the computational layer the XMetoo server will only be needed for the translation task and for manipulating the stdata representations. During the reification process a set of functions, equivalent to the ones of XMeeto but working with the smdata representation, is generated. If all of the functions are generated, we are able to remove XMeeto from MIU, with all modules working with the smdata in cooperation with the Application Model.