Re: Mixing OO and DB

From: JOG <jog_at_cs.nott.ac.uk>
Date: Thu, 14 Feb 2008 05:38:33 -0800 (PST)
Message-ID: <e997e787-1893-41df-926a-11737248e635_at_s13g2000prd.googlegroups.com>


On Feb 14, 3:52 am, David BL <davi..._at_iinet.net.au> wrote:
> On Feb 13, 9:56 pm, JOG <j..._at_cs.nott.ac.uk> wrote:
>
>
>
> > On Feb 13, 2:06 am, David BL <davi..._at_iinet.net.au> wrote:
>
> > > On Feb 12, 9:53 pm, JOG <j..._at_cs.nott.ac.uk> wrote:
> > > [snip]
> > > > Consider /unallocated/ RAM in your PC. Look at 5 contiguous bits at
> > > > random. Are you telling me that the binary number you are looking at
> > > > is "data"? I'd accept that it is a value (albeit a meaningless one)
> > > > but "data"? You really think that?
>
> > > No I don't.
>
> > > When data is recorded on some medium there is a lot of implicit
> > > *knowledge* about how it has been encoded. This knowledge has to
> > > account for all sorts of details, such as what designates a 1 versus a
> > > 0. How many bits in a word? What order do they appear in? Is there
> > > an address bus? How is the address bus organised? The binary
> > > encoding is only a tiny part of it. Obviously we both agree that all
> > > that knowledge is implicit in correctly decoding the data.
>
> > Yes I broadly agree apart from on one key matter (there's a suprise
> > eh) - "knowledge is implict". I contend the exact opposite, and this
> > is my whole point really. The knowledge required must be explicit.
> > That's what makes otherwise random noise, or values, data. In the
> > case of a scientist log book for example what the data means is
> > explicit in a title at the top of the page or in the scientist's
> > head.
>
> You can't make the knowledge explicit because you can't formalise it.
>
> > Another example:
> > "todays lottery numbers: 23, 34, 17"
> > "experimental reults: 23, 34, 17"
>
> > Same values, different data. If you agree with this statement then
> > values != data surely?
>
> You seem to have forgotten that I said data was associated with the
> appearance (ie encoding) of values.

Nicely dodged, but let me try again!

"todays lottery numbers: 23, 34, 17"
"experimental results: 23, 34, 17"

All written down on a bit of paper - same values discussed, but different data. Agree or disagree?

I ask this because if we can distinguish data and values, we must then determine /how/ they are different. You state it is by "encoding" but the two lines above are encoded in the same manner as far as I am concerned, so that cannot be the difference between the two concepts. That is unless your "Encodings" equates to my notion of "Facts", and we are thus agreeing loudly, using different definitions of those terms.

> Encodings have a context, and
> values do not. We don't disagree on whether data is associated with
> encodings. Rather we disagree on what is being encoded. I say data =
> encoded values. (I think) you say data = encoded facts.
>
> > > Our point of contention is rather that I suggest that most generally
> > > the data is nothing other than encoded values, and doesn't necessarily
> > > convey any facts. I'm assuming that the knowledge implicit in the
> > > encoding of the data is by definition not part of the data itself,
> > > whereas I think you are suggesting it is part of the data.
>
> > Yes I think that's an excellent breakdown. Its all just down to where
> > we draw the lines I guess...
> > Brian: Data is encoded values. I need to know externally what they
> > represent.
> > Jim: Data is encoded values plus an denotation of what they represent.
>
> Did you mean to say Brian?

No I meant to say David. Apologies.

>
> Do you agree you cannot formalise what the values represent?

Yes, imo no "meaning" can be represented via a purely descriptive formalism. One always needs some component situated in the real world for that. But obviously we can formalize communicated statements of fact.

> [schnnnip]
> > > > > C.Date distinguishes between a value (that by definition doesn't exist
> > > > > in time and space), versus the *appearance* of a value which appears
> > > > > in time and space and is encoded in a particular way.
>
> > > > Is this what your view of the terms is based upon?
>
> > > These definitions seems reasonable to me.
>
> > This seem overly philosophical to me. Surely we don't need metaphysics
> > to know that if someone hands me a bit of paper with: "1.00, 0.376 and
> > 0.904" on it, well that's just a list of values. However if if someone
> > hands you a bit of paper with "Surface Gravity - Earth:1.00, Mars:
> > 0.376 and Venus:0.904", or tells you those denotations, then we have
> > data ;)
>
> You have repeatedly chosen examples that suit your argument, whereas
> according to our disagreement only I that have that privilege!
>
> Jim:
> In all examples, data is useful to the recipient and
> represents facts

Yes, of course, because the poem example is much harder for me to deal with ;P

>
> David:
> 1) In all examples, data is useful to the recipient and
> represents values; and
> 2) There exists example where data is useful to the recipient
> and doesn't represent facts
>
> Since a tuple of a relation is a value and it also represents a fact
> it is clear that my definition of data encompasses yours.
>
> We can both easily think of examples where (so called) data is useless
> to the recipient. Let's agree and say that's not actually data. That
> only leaves one possibility for proof by counter example: I provide
> an example where the data is useful to the recipient yet doesn't
> convey any facts. The sending of a poem or an image without any
> additional context is an example.

Well put. I contend that you can't do this, and that a poem or image as described is not an example of data, but merely values. You are saying to me "a poem is data. It is clearly not a fact. Ergo, pwnage." But you are already assuming it is data in the first step. I say its not, and cannot follow why you would think it is. Like a "22". That's not data but, if I was a numerologist say, I would still find the value interesting.

So to me the poem is just a value. Its only data when I say this thing here, X, has role Y. A picture is just a picture. Even if its, say, a biochemistry picture of a cell membrane. _However_ if that picture is then put in a log book, under "image of neurostem cell from experiment B", its data. This accords to tradtional definitions.

I am offering you examples where you have an item that you would not describe as data, and showing how it is turned into something that is generally described as data. All best, have found the conversation so far well articulated, even if we don't agree.... Jim.

>
> People download web pages (which are basically just encoded values)
> into their WWW browsers all the time without any more context than
> following a hyperlink. They often don't find out whether it's useful
> or relevant until they read it. In many respects the WWW can be
> regarded as a big collection of encoded "interesting values" indexed
> by content without any additional context.

Web pages are just values. They of course may describe data in their contents. Boink. Received on Thu Feb 14 2008 - 14:38:33 CET

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