Giovanni Scriba's registrations stand out for their internal variety. Later notaries provide a greater quantity of contracts per year for Sicily and elsewhere, as business blossomed, but most of these are reduced to simple formulae. The more consistent the material the better, from a statistical point of view; but, given the lacunae in the notarial registers, even a stable set of statistics does not take matters very far. Giovanni Scriba comes to the rescue with information about trade routes, commodities and profits; and, in addition, he provides a wide enough spread of contracts to illustrate the mercantile careers of many Genoese citizens and denizens. For, at a time when Genoese trade was still edging forward into new areas of influence, and expanding its contacts with existing markets, the notaries did not regard commercial acts as so commonplace that they could easily be standardised. Moreover, Giovanni's evidence gains added proportion from its unique antiquity. It provides a starting point for the study of several phenomena, such as the rôle played by the aristocracy in overseas trade. In these circumstances it seems appropriate to ask a rather different series of questions of the earliest evidence from the questions that will be asked of late-twelfth-century notaries. On the basis of Giovanni Scriba's registrations it will be possible to identify elements of continuity – elements strictly commonplace in the 1180s and 1190s, or elements that underwent changes in emphasis and scale as the century progressed.

Among economic historians of this period there has been a tendency to catalogue items of merchandise, and to lay emphasis on the wide variety of luxury goods that came in small quantities under exotic names to Genoa and Sicily.