Abstract
How have Dutch instructive texts changed in the course of the last century? This question is the topic of a research project presented in this article. First, we give some insight into the kind of documents we have collected in our corpus. The oldest instructive texts date from the beginning of the nineteenth century. But for most technical devices, the tradition of adding an instructive text starts about 1925. After that we present a few results of the investigations: the disappearance of persuasive passages and of realistic representations of human beings. Finally, we give a more detailed sketch of the development of the algorithmic style.