David E. Millard, Danius T. Michaelides, David De Roure, Mark J. Weal Beyond the Traditional Domains of Hypermedia

OHP to FOHM OHSWG investigating interoperability between OHSs Open Hypermedia Protocol Different domains of hypermedia (Navigational, Spatial and Taxonomic as examples) OHP-Nav What about a unified model to cover all three? Fundamental Open Hypermedia Model (FOHM)

FOHM Associations – generalised links Referencable Associations – Associations can connect to each other Context – to define visible parts of the hyperstructure Rules – ‘collapsing’ structures when context fails Behaviour – opaque objects containing client instructions Stand-alone OHS called Auld Linky that implements it all

A Navigational Link in FOHM DDS Link Association Binding Context Reference Data Behaviour

A Navigational Link in FOHM DDS Link Association Binding Context Reference Data Behaviour

A Navigational Link in FOHM DDS Link Association Binding Context Reference Data Behaviour

A Navigational Link in FOHM DS Link Association Binding Context Reference Data Behaviour

The Domains of Hypermedia The Universal Set of Structure Nav Space Tax The OHP view of the hypertext domains

The Domains of Hypermedia The Universal Set of Structure Nav SpaceTax The FOHM view of the hypertext domains

The Domains of Hypermedia The Universal Set of Structure Nav SpaceTax FOHM covers more than the original 3 domains FOHM

Real-world Links Equator City Project Linking over ‘real-world’ spaces Visitors move around museum with PDA and positioning system Auld Linky serves up links to new destinations Real-world links need multiple descriptions –Why should the visitor move? –What have they just moved to? –(How do they move there?) Descriptions can be multi-media (e.g. audio)

Real-world Links SRCDEST REAL WORLD BEFORE Adult AFTER Child audio BEFORE Child Link text

Virtual Documents A tour over many media fragments Compiled into a document by the application Context makes membership of the composite conditional Similar to conditional transclusion Structure is the same as a guided tour NB a guided tour is not a part of OHP-Nav, Space or Tax

Virtual Documents text 2 pic Composite Document 1 text 2 Composite D text 4 pic 5 text Composite Document (list)

Virtual Documents text 2 pic Composite Document 1 text 2 Composite D text 4 pic 5 text Composite Document (list)

Virtual Documents text 2 pic Composite Document 1 text 2 Composite D text 4 pic 5 text Composite Document (list)

Virtual Documents text 2 pic Composite Documenttext 4 pic 5 text Composite Document (list)

Glasgow Servlet II

Sculptural Hypertext Makes a distinction from traditional ‘calligraphic hypertext’ Calligraphic Hypertext adds links until network is complete Sculptural Hypertext removes links until network is complete Each link has conditions that must be true before it is visible… …and actions that determine whether new conditions are true FOHM formalises this

Generalising Links SD Specific

Generalising Links SD Local

Generalising Links SD Generic

Generalising Links SD Context (Conditions) Behaviour (Actions) Sculptural

The Domains of Hypermedia The Universal Set of Structure Nav SpaceTax Where would these new structures go? FOHM Real-world Composite Documents Sculptural

Context vs. Structure With real-world links: is location part of context or an anchor? I.e. are real-world links specific or sculptural? This applies to all media documents Early work described anchors as context on the end of a link Anchors quickly became absorbed into mainstream models Should we be doing the same with our contextual elements Or should anchors become contextual again

Conclusions There are interesting structures lying beyond the domains of hypermedia identified by OHP There are new types of hypertext lying in the overlap between them (sculptural hypertext) Was the OHP-Nav link powerful enough? –It cannot express our real-world links –It cannot deal with sculptural hypertext Context is powerful, useful and increasingly important Should we be trying to specify what is currently contextual Or Contextualise what is currently structural?