A vertical reading should demonstrate the coherence of a pure type, which according to the Weberian ideal type is a construction of ‘heightened’ concepts for which some evidence is available in reality, even if these models do not exist as such in reality. There are sufﬁcient indicators in the country cases to assume an adequate coherence, and perhaps even a singular causal model between the type of measurement, the type of incorporation, and the type of use. The reverse single causation could also be applied in an ideal type. If there is a policy to develop a particular type of use, then there will be a need to develop a related and particular type of incorporation, and hence a particular type of measurement. Obviously, the typologies of measurement, incorporation and use, are coherent within an ideal type. These models are described in Chapters 4, 5 and 6. Illustrations are provided to support the ‘heightening’ and show that there is sufﬁcient evidence to support the probability of each type. Chapter 9 provides key elements of a fourth ideal type.