In the validation phase of the lexicon morphosyntax work within EAGLES, the production of guidelines, i.e. clear tests and explicit criteria for the encoding of lexicons on the basis of the EAGLES recommendations, has been undertaken for English, French, German and Italian. The guidelines are currently available for French (EAGLES, 1995c), German (EAGLES, 1995a), English (EAGLES, 1995b) and Italian (EAGLES, 1995d).
In the specifications of the EAGLES recommendations, an important aspect in the production of practical criteria for the encoding of lexicons is also highlighted, namely the dependencies between different attribute-value sets and the constraints in the application of an attribute/value in presence of another attribute/value. These phenomena are represented in terms of typed hierachies of each feature.
Why has a typed hierarchy been chosen? This was considered a good means of translating dependencies and constraints into a typed feature based formalism and of handling them with rigorous computational techniques rather than leaving them to human control. In the creation of these typed hierarchies some values/attributes proved to be necessary for representing the structure of the attribute-value and for handling computationally dependencies: these features have been integrated in the tables and are now part of the recommendations.