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The 'Digital Object Types' Issue
- 1. The ‘Digital ObjectTypes’ Issue Andy Jackson BL
- 2. Where are wenow, technically? • Current digital object property architecture: – PLATO captures institutional requirements. – Can link them directly to ‘technical’ properties, e.g. those extracted via the XCL tools. • Planets has no other ‘Digital Object Properties’ – Conceptual models and definitions are considered institutionally dependent. – Note that O.T. templates can allow common property models and definitions to emerge. • Should we try to define them? How?
- 3. Original Testbed PropertyModel • Evaluate migration services based on comparing ‘Intellectual Properties’ of the input and output. – Defined as Properties of Types of Intellectual Object. – Extract relevant Intellectual Properties from initial and final Digital Objects. – Intellectual Properties judged same/similar/different. – Evaluate service/tool based on how well the properties were preserved.
- 4. Digital Object ‘Types’ •In TB, an interpretation of the rendered object. – i.e. a scanned TIFF of a journal article could be interpreted as both an Image and a Document, employing properties from both. • For comparison, in XCL, ‘type’ would refer to the information model which encompasses the information content of some set of formats. – e.g. the image model which covers PNG, TIFF, etc.
- 5. Significance & Objectivity •General realisation that ‘significance’ is at least very difficult to define. • Significance of properties differs between Planets Partners. • Can we define ‘objective’ properties? – Requires a shared system of property definitions. – Attach ‘significance’ to these properties in PLATO.
- 6. Requirements For IntellectualProperties • Requirements – Must pertain to the rendition, i.e. transcend file format. – Must be institutionally independent, -> ‘objective’. – Must be self-consistent, implying one system of intellectual properties per rendition ‘type’. – Must be concrete, i.e. measurable in principle. – Must be capable of completely describing the rendered form (required in order to be ‘objective’, to be capable of verifying ‘authenticity’ for all definitions of ‘significant’). • This has proven very difficult!
- 7. Problems with thatmodel • Not clear if some of those requirements are even possible to meet in principle. • Clearly a very large amount of work. – Even if achieved, does not include enough technical properties that are of interest. • e.g. format properties with non-trivial consequences. Does service preserve the method of compression? • e.g. properties of services (speed etc), agents, technical environments, etc. • So, where should we focus our efforts?
- 8. What kind ofproperties? • If we do want higher-level properties… – ‘Type’ Properties? – Properties of the Rendition? • What degree of coverage, of what? – Aim for completeness, but narrowly focussed? – Sparse, but concentrate on risks and flaws? • Explicitly define comparative properties? – Don’t just want compare properties extracted from files. – e.g. define a property that means the RMS difference between two images when rendered (c.f. XCL).
- 9. Ideas for howto do it. • Use DOPWG(?) to pool knowledge only? – Park it until Planets 2. • Use DOPWG as seed for long-term working group? • Use DOPWG to monitor PLATO templates for emergence of common property models? – Look for commonality and encourage convergence? • Use DOPWG to generate a property model? – Produce a document, XML Schema, an ontology, a dictionary, or PLATO O.T. template?
- 10. Summary • Should weattempt to define common ‘Digital Object Properties’ in Planets (1)? – What kind of properties? • ‘Object’ or ‘Rendering/Performance/BetterWord’? • ‘Comparative’ as well as ‘of-an-instance’? – How to proceed? • Observe, steer, or control? • Define inside or outside PLATO? Augment ontology? • Needs well-defined objectives and allocated effort!
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