He was one of the foremost scholars in the field of Austronesian linguistics,[1] publishing extensively on the reconstruction of Proto-Austronesian phonology and on subgrouping within the language family, the latter principally by means of lexicostatistics.
[2] The youngest son of a rabbi and his wife who had immigrated from Kiev, Ukraine, "Iz" (as he was known to friends) grew up speaking Yiddish at home and studying Hebrew at Gratz College in preparation for rabbinical training.
After the war, he did fieldwork on two more genetically and typologically disparate Austronesian languages, Chuukese (rendered as "Trukese" at that time) and Yapese, as a member of the Tri-Institutional Coordinated Investigation of Micronesian Anthropology sponsored by Yale University, the University of Hawaiʻi, and the Bernice P. Bishop Museum.
[2] At the same time, he began applying his comparative method to revise and elaborate phonological reconstructions that had earlier been published by Otto Dempwolff (1934–38).
His application of the same methods to his own new data from Chuukese led to a monograph On the history of the Trukese vowels (1949), which brilliantly demonstrated how the nine vowels of Chuukese had derived quite regularly from the four-vowel system Dempwolff had reconstructed for Proto-Austronesian.