The field of Visualization is getting mature. Many problems have
been solved, and new directions are sought for. In order to make
good choices, an understanding of the purpose and meaning of visualization is needed. Especially, it would be nice if we could assess what a good visualization is. In this paper an attempt is made
to determine the value of visualization. A technological viewpoint
is adopted, where the value of visualization is measured based on
effectiveness and efficiency. An economic model of visualization
is presented, and benefits and costs are established. Next, consequences for and limitations of visualization are discussed (including
the use of alternative methods, high initial costs, subjectiveness, and
the role of interaction), as well as examples of the use of the model
for the judgement of existing classes of methods and understanding
why they are or are not used in practice. Furthermore, two alternative views on visualization are presented and discussed: viewing
visualization as an art or as a scientific discipline. Implications and
future directions are identified.