In the framework of the Working Group "The Learned Practices of Canonical Texts," Paolo Visigalli investigated the relation between the ritual use made of the Vedas and their codification as canon. In doing so he aimed to highlight the importance of the concept of mantradevatā, "the deity who presides over the ritual formula," as a system of classifying the Vedic canon.
As recent scholarship has remarked, the employment of Vedic verses for ritual purposes played a significant role in bringing about an emic understanding of the canon according to which the Vedas are, in the first place, a corpus of sacrificial formulas. But as tradition reiterates, ritual is ineffective if the sacrificer does not know the deity to whom the ritual formulas are dedicated. Therefore, the cognizance of the deity of the formula (mantradevatā) is an essential factor for the success of sacrifice. In this regard Paolo Visigalli explored how different texts (mainly the Nirukta, Bṛhaddevatā, Anukramaṇī, and Mīmāṃsā-sūtra) set forth hermeneutic techniques for identifying the right deity (devatā) of each Vedic formula.