In this book, a person-oriented perspective was presented and a tool ehest of basic methods for carrying out research within this framework was described and exemplified with empirical research. Taking this theoretical framework seriously has far-reaching implications for how empirical research is carried out. However, as pointed out before, it is important not to confuse the person approach with the methods commonly used to carry it out, for example, duster analysis, and so forth. Indeed, a wide range of methods is possible for use within the person approach and the choice should always be made in such a way so that the method matches the specific problem. For reasons that should be clear to the reader by now, in the most common types of situations, it is desirable that the method used captures, as much as possible, the system as a functioning whole. This point is now elaborated.