Re: [xml-dev] The impact of data format selection on applicationdevelopm

[Roger L Costello <costello@mitre.org>]

Hi Folks,

Norman made an excellent point about the importance of "context" in understanding data. Normal wrote:

> as has already been discussed in this thread, there's significantly
> more to CSV or TSV than meets the eye (escapes, line-endings, 
> and so on), so this is 'simpler' only for a recipient who has seen 
> this before and knows what to do.  _In that context_, the data 
> description is short, and appears simple.
>
> So 'simple' data formats are actually 'high-context' data formats (compare [1]).
>
> Note that in that description I didn't mention that I'd expect the integer 
> _not_ to include a comma (which is useful only for display, and which 
> would conventionally be regarded as hostile in a transmission format), 
> and I did choose to add a little explicit context in mentioning the units 
> of the second column (you _did_ mean km, didn't you,... hmm?).  So 
> I've thoughtfully chosen what context to make explicit, and expected 
> that the recipient of the description will know the Right Thing To Do.

I think that Norman is asserting that XML provides more contextual information and therefore is a superior data format. XML is a high-context data format. I would like to challenge that assertion. Consider this highly plausible XML representation of the data:

<Document>
    <Row>
        <li>Missouri River</li>
        <li u="mi">2341</li>
    </Row>
    <Row>
        <li>Mississippi River</li>
        <li u="mi">2340</li>
    </Row>
    <Row>
        <li>Yukon River</li>
        <li u="mi">1979</li>
    </Row>
    <Row>
        <li>Rio Grande</li>
        <li u="mi">1759</li>
    </Row>
</Document>

First, that is a complicated data format. If the consumer is not an "XML person" then a huge amount of explaining will be required before the consumer can even start to understand the data. Okay, now that the consumer understands what all those angle brackets mean, you will have to then explain the data. Is the XML helping with understanding the data? Is the XML helping to understand the context? I don't think so: What's "li"? What's "u"? What's "mi"? I assert that the same amount of explanation must accompany the XML as must accompany the super simple data format. But what is different about the super simple data format is that the explanation of its data format (a series of lines, each line containing two fields) is immediately discerned. 

Thoughts?

/Roger