The Mystical Side of Data Modeling
It's common for data modeling to be regarded as a somewhat mystical activity in the IT world, and data modelers and architects are sometimes considered the mystics of IT. None of the other IT people really understand what they do. Who understands why we use data normalization, the relational anomalies, and 3rd, 4th, and 5th normal form? The business analysts give the data modeler their business requirements, and then they get interrogated: "Why do you need this? How are you going to use that? What's the definition of this term?" Then the DBAs and software developers look at the emerging logical model and wonder why the modeler used such funny data element names and what all these extra boxes and lines are. Then everyone waits for the database structures, hoping they can figure out how to get the information out by coding the application programs. Once the database is delivered, everyone wonders how that abstract blueprint of boxes and lines can possibly deliver the correct business information.
The premise of my book Models, Metaphor and Meaning is that data models use metaphor to express their meaning.
For example, the meaning of the following conceptual model is easy to grasp in one gulp.
Ludwig Wittgenstein's Picture Theory of Meaning as developed in his Tractatus Logico Philosophicus explains how we use words and sentences to express meaning. It also applies to how we use data models to express some very complex business requirements. Wittgenstein was one of the most influential philosophers of the 20th century, and he had a lot to say about meaning and the semantics of representation in the Tractatus. But his philosophical writings are extremely difficult to read and understand. Most of the Tractatus is written in the form of numbered aphorisms. But his aphorisms seem to exactly describe how models use metaphors to convey their meaning.
2.1 We picture facts to ourselves.
2.11 A picture presents a situation in logical space, the existence and non-existence of states of affairs.
2.12 A picture is a model of reality.
2.13 In a picture objects have the elements of the picture corresponding to them.
2.131 In a picture the elements of the picture are the representatives of objects.
2.14 What constitutes a picture is that its elements are related to one another in a determinate way.
2.141 A picture is a fact.
Wittgenstein takes great pains to explain that his special use of the word picture is NOT a mental image of some aspect of reality. 2.12 explicitly states, "A picture is a model of reality." In 2.15 he explains the difference between the structure of the picture and the form of the picture.
2.15 The fact that the elements of a picture are related to one another in a determinate way represents that things are related to one another in the same way. This connection of the elements of the picture is called its structure and the possibility of this structure is called the form or representation of the picture.
It is evident Wittgenstein's Picture Theory is really trying to explain how we use mental concepts to model reality.
One of the most important and mystical theses in Wittgenstein's Tractatus is his insistence on the difference between what can be spoken about on the one hand and what can only be shown but not said on the other.
6.522 There is indeed the inexpressible. This shows itself; it is the mystical.
6.54 My propositions are elucidatory in this way: he who understands me finally recognizes them as senseless, … (He must so to speak throw away the ladder, after he has climbed up on it.)
7 Whereof one cannot speak, thereof one must be silent.
One way to illustrate the concept of showing not saying is by understanding how a parable shows its meaning. Let's use for our example the parable of the Emperor's New Clothes. An Emperor commissions his weavers to create a new suit of clothes, and no one dares say they do not see any suit of clothes on him for fear of looking stupid. Then a child cries out, "The Emperor has no clothes." Although we may not remember the exact words that set up the story, our understanding of the moral of the story is based on how the emperor's foolishness is shown, but not explicitly stated, in the story. In this way the ethical lesson is shown, not said. This is the same conceptual device that's used in metaphors and models. A metaphor maps something familiar onto something else in order to emphasize some hidden or interesting aspect. The mapping is what's comprehended when we understand the metaphor, but the mapping is only shown and not said. Likewise, models show the big picture of topics or entities within a subject, and they are conveniently mapped into their elements and relationships in order to generate the information system. In this way, developing and comprehending data models appeals to our mystical side.
The data modeler has to be an evangelist for good data management practices, like minimizing data redundancy. The data model has to be sold to skeptical developers and managers. Creating the data model appeals to the mystical side of modelers and architects.
Data modelers and data architects who develop and manage models in their everyday work are unconsciously using complex metaphors to communicate. They take pride showcasing their latest creation but they are really communicating on a deeper cognitive level. Their models cleverly show their meaning and at the same time are able to tell their specifications for the target database to the developers. Developing data models is a natural extension of metaphorical conceptualization which is basic to human thought.
 Ludwig Wittgenstein, Tractatus Logico Philosophicus, New York: Harcourt, Brace (1933), [Reprinted, with corrections].
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