A Doubly Projected Analysis for Lexical Tables

The presentation aimed at showing how the introduction of external information in analysing a lexical table can enrich interpretation of factorial maps. The methodological frame is given by Principal Component Analysis onto a Reference subspace, a method based on the orthogonal projection of a correlation structure on the space spanned by an external set of explanatory variables. In previous papers, the idea of a projected lexical analysis has been introduced, using a single reference space, where to represent the behaviour of terms, while information on documents were used for building aggregate lexical tables. Here we consider external informative structures both on documents and terms, i.e. on rows and columns of a lexical table. The proposal consists in a double projection strategy, which additionally involves the document behaviour, related to external information. An application on the Italian Universities didactic supply is shown.