Willem is an associated researcher at the KNIR, involved in the KNIR projects the Tappino Area Archaeological Project and The Impact of Roman Imperialism in the West project. He studies (western) Mediterranean archaeology, emphasising on the ancient rural landscape and material culture in the first millennium BCE and the early first millennium CE.
He has been a part of the staff of multiple KNIR campaigns in Italy and Portugal for several years, and is currently responsible for the organisation of the ongoing pedestrian field- and geophysical surveys, as well as aerial and excavation campaigns. He is also responsible for the (coordination of the) analysis of these projects’ finds both at the Centro Didattico Internazionale di Studi Archeologici (CeDISA) in Jelsi (Molise) and in the KNIR lab for material culture studies.
He has participated in many different archaeological excavations, surveys and other fieldwork projects in Italy (in Campania, Lazio and Molise), as well as in Greece, Portugal and Spain.
He is one of the editors of the KNIR-affiliated magazine Roma Aeterna.