This project aims to establish criteria by which results from language contact studies can be used to strengthen the field of historical linguistics. It does so by applying the scenario model for language contact studies to a number of concrete settings, which differ widely in their level of aggregation and dime depth: the languages of the Amazonian fringe in South America, the complex multilingual setting of the Republic of Suriname, the multilingual interaction of immigrant groups in the Netherlands, and two groups of multilingual individuals. New methods from structural phylogenetics are employed, and the same linguistic variables (TMA and evidentiality marking, argument realization) will be studied in the various projects. In the various projects, use will be made from a shared questionnaire, so that comparable data can be gathered. By applying the scenaio model at various levels of aggregation, a more principled link between language contact studies and historical linguistics can be established.