This dissertation examines argument quality and persuasion. It provides insight into the specific characteristics that determine the quality of the argument from authority, the argument from cause to effect and the argument from example. These three types of arguments can be used to support the pragmatic argument: a type of argument in which the acceptability of an act is defended by referring to its effects. This study fruitfully combines a normative and a descriptive approach to argumentation. The first part of the dissertation deals with norms that, according to argumentation theory, lay people should use for argument evaluation and norms that lay people do use for argument evaluation. The second part is about the role that these norms might play in the persuasion process. It reports on experiments on the relation between normative argument quality and actual persuasiveness. The results not only indicate to what extent normative-theoretical criteria and laymen criteria correspond, but also show the degree to which the characteristics that laymen claim to make up a strong argument match those that persuade them during central processing. Therefore, this work is of interest to researchers concerned with argumentation studies and persuasion research, and to all having a curiosity about the nature and function of argument quality