Representation is fundamental to working with knowledge in my view. I'm collecting my thoughts here.
What is representation?
Ad hoc sketches, informal qualitative models, scenario construction, concept maps, rule sets, structured text all serve as representation, reflecting the expectations and experience of their creators, they connect collaboration to future use. They serve a dual role: (a) to facilitate design and critique and (b) to serve as the holder for the product to be, they are affordances in design, which they can enhance or inhibit. Representations, clarify, extend, complete and move unique experiences and abstract ideas toward the essential and typical. Representations are material, they allow ideas and experience to have an independent existence in an externalized form, they help to capture emergent thought. Like a lump of clay, a representation is tangible, it can be pointed to, passed around, played with. It takes thought experimentation one step further, eliciting new ideas.
Mediating in collaboration
Prototyping, 'strawman' and mock-up activities allow particpants to draw on their experiences and practices more directly than abstract descriptions. Representations mediate the relation between collaborators and their products, between individuals in a group, between the group and their sponsors and between the group and their users / market. Once captured in a representation, there is a resistance that sets in as descriptions are manifest & objectified that tends to balance the affordance offered. It is the multitude of interpretations that carries the strength of a representation rather than the consensus around shared meaning.
Representation as container
Boundary objects (concept maps, ontologies, source documents) serve as a vehicle, container and carrier, for ideas. When a representation crosses boundaries, there is a loss of meaning (reification) and context, which is counter-balanced by an opportunity for new negotiations, different views and altered meaning. This points to the importance of establishing rationale & context in use or practice, an essential non-represented aspect associated with any formalism. All representations are situated in use. An important aspect of a memory object is its trajectory, i.e. the consequences of later use (see Ackerman & Halverson 1999, in BoundaryObject
Representation as mapping
Most often we look upon our representations as one for one mappings.
Henry Seiler, in "Managed business rules: A repository-based approach" PC AI July / August 1999 16-19, http://www.rulemachines.com/brs/whitepaper.htm talks of business and code developers interaction around business rules (a BO) and gives the roles & architecture of a rule object repository. Allows business types to participate directly in design, preserves critical documentation, enables off-line testing, helps with rapid response to business change, an IC reporting tool, separates representation and inference. see http://www.rulemachines.com
This is covered in greater depth in KmFaq. It can be used to capture solutions to common problems, used for self-help and perhaps a little bit of training. There are some quite sophisticated FAQ engines for reasoning and presentation.