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I’m kicking off 2012 with a couple of things I just don’t get. Here’s the second one: What exactly is a ‘conceptual data model’? Why in the world is it called that instead of just ‘concept model’?
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Did you ever pause for a while to ponder the meaning of the term “data”? Most of us don’t. The term is so familiar and pervasive we simply take it for granted. For IT professionals, “data” is about as basic as it gets.
Taking terms for granted, unfortunately, is the surest path to confusion. It’s the deep assumptions about the terms lying at the very heart of a subject matter that usually trips us up. So let’s take a moment to examine the meaning of “data”.
Just so you know where this is headed, I’m embarking on a full frontal assault on the term “conceptual data model”. I’ve disliked that term for years. I think we should kill it off once and for all. Why? Three fundamental reasons:
- No business person would naturally say “conceptual data model” in everyday business conversation. If we mean something by “conceptual data model” that business people should be able to talk about, then why have a name for it they can’t easily understand? Jargon just makes things harder.
- I believe what you really mean when you say “conceptual data model” is simply “concept model”. If “conceptual data model” doesn’t mean that, then what in the world does it mean?!
- “Concept model” has recently been adopted by SBVR 1.1 replacing “fact model”. The SBVR reasoning for the switch is directly related to this discussion, but I’ll save it for some other post.
Why Not “Conceptual Data Model”
The Wikipedia entry for “data (computer science)” says, “… information in a form suitable for use with a computer. The entry adds, “Data is often distinguished from programs … data is thus everything that is not program code.”
Now let’s substitute “… information in a form suitable for use with a computer” for “data” in “conceptual data model”. The result of the substitution is “conceptual information (in a form suitable for use with a computer) model” or simply “conceptual information model”. What exactly does that mean? As far as I can tell, not much at all!
By all rights we should be permitted to terminate the analysis there. In IT the Wikipedia definition is what “data” has meant for well over half a century. If you’re interested and have the patience, however, let’s be charitable and look more broadly at the term “data”. See the footnote[1] (long). Skip it if you like – it leads nowhere and life is short.
As the footnote indicates, any attempt to make sense of “conceptual data model” through fair-minded dictionary analysis of “data” leads to nonsense or a dead end. So the term “conceptual data model” must have an origin all its own.
Indeed it does – one definitively IT-based. Reviewing the Wikipedia entry for “conceptual data model” we find the synonym “conceptual schema”. “Conceptual schema” is a technical term dating at least from the 1970s. I can vouch for the overall accuracy of the Wikipedia entry since I wrote several books touching on the subject in the 1970s.
Ironically, Wikipedia provides a great definition for “conceptual data model”: a map of concepts and their relationships. Bingo! So why all the mumbo jumbo? Why not just say “concept model”?! Let’s toss “conceptual data model” and be done with it!
[1] Definitions of “Data” in Merriam-Webster Unabridged Dictionary
1a: … SENSE-DATUM : an immediate unanalyzable private object of sensation *a sharp pain, an afterimage …*
Surely that’s not what a “conceptual data model” is about.
1b(1) material serving as a basis for discussion, inference, or determination of policy *no general appraisal can be hazarded until more data is available*
Most meanings of “material” are physical (e.g., metal, wood, plastic, fiber), however one [1b(2)] is not: something (as data, observations, perceptions, **ideas**) that may through intellectual operation be synthesized or further elaborated or otherwise reworked into a more finished form or a new form or that may serve as the basis for arriving at fresh interpretations or judgments or conclusions (emphasis added).
For the sake of argument, let’s assume that “data” in “conceptual data model” is meant as “ideas”. So “conceptual data model” then becomes “conceptual idea(s) model”. What exactly are “conceptual ideas”? Or more precisely, what ideas are not conceptual?!? So in the very best case, this definition of “data” results in the awful signifier “conceptual idea(s) model”.
1b(2) detailed information of any kind
You can go through the various definitions of “information” if you desire, but I’ve already asserted that “conceptual information model” is nonsense. This whole matter can’t be all that hard(!).
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{ 1 comment… read it below or add one }
Hi Ron,
thanks for this. It makes a lot of sense to me and I completely agree.
I think a lot of the confusion comes from the fact that “concept model” sounds/feels very vague. Everything can be concept and therefore a concept model could be about everything, whilst “concept data model” provides an idea of what is discussed.
Maybe the missing “qualifier” is that we only want to discuss the relevant business concepts when we talk about a normal business environment? Would therefore the wording “business concept model” point in a better direction? It feels better to me, but that might steam from old, bad habits.
Cheers,
Klaus