Trained in Classical Archaeology, he specializes in Roman and Late Antique art and architecture in the provinces of Syria-Palestine. His interests lie in various aspects of town-planning, architectural design, mosaic art, synagogues, Jewish art, as well as the evaluation of archaeological finds in light of the socio-cultural behavior of Jewish society and its dialogue with Graeco-Roman and Christian cultures. As director of the Sepphoris excavations on behalf of the Hebrew University of Jerusalem since 1990, his work has contributed greatly to the understanding of the architectural development