[Moims-rac] significant properties vs. representation information

[Barbara Sierman]

Interesting discussion,  a "working definition" for significant
properties, based on literature and discussions that is sometimes used
is:

"an important property of a certain digital object, as experienced by
the user. Signicifant properties can be classified by five aspects of a
digital object: structure, content, context, appearance, and behaviour.
Examples: text (content), chapters (structure), metadata (context),
colour (appearance), zoom-functionality (behaviour)."

"as experienced by the user" implicates that before ingesting these
properties are also detected, otherwise you could not take the right
actions to do right to these properties.

The relation with Representation Information is clear, the examples of
Cal are exactly the problems we had in our discussions. The use of the
word Significant Property instead of Representation Information may be
is related to the fact that Significant Property is such a pithy
saying... But it would be nice if we could refine the definitions more.


 
 
Barbara Sierman
Digital Preservation Officer
 
Koninklijke Bibliotheek
PO Box 90407
2509 LK Den Haag, The Netherlands
 
+31 70 3140109
barbara.sierman at kb.nl

www.kb.nl

> -----Oorspronkelijk bericht-----
> Van: moims-rac-bounces at mailman.ccsds.org [mailto:moims-rac-
> bounces at mailman.ccsds.org] Namens Cal Lee
> Verzonden: maandag 21 januari 2008 14:24
> Aan: moims-rac at mailman.ccsds.org
> Onderwerp: [Moims-rac] significant properties vs. representation
information
> 
> I agree with earlier comments that there's a strong overlap between
> representation information and significant properties.  Here's the way
I
> conceive of the difference, which I hope is helpful:
> 
> - Significant properties are the characteristics of a digital object
> that are important be able to reproduce over time, even if the
> underlying hardware and software changes.
> 
> - Representation information is the technological means to instantiate
> the significant properties within a given hardware and software
> environment (or set of hardware and software environments).
> 
> One hopes to be able to create/capture and preserve representation
> information that provides for as wide a set of supported hardware and
> software environments as possible (i.e. building a preservation
> environment that is relatively robust to hardware and software changes
> over time).
> 
> For a given digital object (or set of digital objects), the properties
> that are deemed to be significant (and thus necessary to reproduce
over
> time) and required representation information can both change over
time.
>   For example, a repository may have found it extremely important to
> maintain many aspects of how a document was rendered on the screen,
but
> given changes in the needs of the Designated Community, the page
> rendering may become fairly unimportant, but the ability to search
over
> the parse the text for analysis is essential.  Examples of the changes
> in required representation information over time are all over the OAIS
> and the digital preservation literature (e.g. changes in the character
> encoding schemes or file formats).
> 
> In short, the difference between the two terms is based on their
degree
> of implementation granularity.  Because this is a continuum, there
will
> always be boundary cases, in which people disagree about whether
> something should be considered a significant property or an element of
> representation information.  With that said, I think there are many
> cases in which the distinction is pretty clear.  Some examples:
> 
> 1)
> Significant property = color in which the text appears
> 
> Representation information = mechanism for encoding what color the
text
> is, color space that accurately maps that color name to a specific RBG
> or CMYK value for purposes of rendering on screen or paper
> 
> 2)
> Significant property = appearance of diacritics on all characters
> 
> Representation information = character encoding scheme that accurately
> identifies and supports all such characters, font(s) that includes all
> the glyphs needed to render the letters and their diacritics
> 
> 3)
> Significant property = ability to accurately identify the level of
> precision of a particular data element in a data set
> 
> Representation information = codebook, data dictionary or other form
of
> documentation that indicates the level of precision
> 
> 4)
> Significant property = ability to then support the level of precision
of
> the above data element
> 
> Representation information = data type that supports that level of
> precision (e.g. floating point number with a sufficient number of
> decimal places)
> 
> I hope all of this makes sense.  I certainly think these are important
> distinctions for digital curation professionals to consider and
clarify.
> 
> 
> =========================================================
>    Cal Lee                            callee at ils.unc.edu
>    University of North Carolina, Chapel Hill
>    School of Information and Library Science
>    Phone: 919-962-7024
>       "Memory is attention in the past tense."
>                       - Daniel Goleman, 1985
> 
> 
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