The MADDLAIN project aims to analyse the behaviour and the needs of different audiences with regard to digital access to the collections offered by the CegeSoma, the Royal Library of Belgium and the State Archives of Belgium. In the scope of this project, I presented some of the results of the qualitative survey conducted with professional researchers in the Humanities, who form an important category of the public using the collections of the above institutions. Understanding how researchers work, and particularly how they seek, collect, and manage information can help us improve online services and tools.