 His dissertation was on the genealogy of the Oceanic languages of western Melanesia, and contained an early reconstruction of Proto Oceanic.It also introduced the concept of a linkage, a group of languages that evolves via dialect differentiation rather than by tree-like splits.Together with Andrew Pawley and Meredith Osmond, Ross has contributed to the Proto-Oceanic Lexicon Project, which has produced several volumes of reconstructed Proto-Oceanic vocabulary in various semantic domains.