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Identify all actions that can be performed on the objects

Actions and functions are the operations that can be performed on these 6 node types and 12 link types. Actions can be generic, explicit, or control-like.

Generic Actions

The ability to create webs of information from nodes and links between nodes is an inherent property of hypertext. Facilities to add, modify, and delete nodes and links can be considered as generic actions. That is, though these actions have a common meaning, their execution depends on the kind of object they act on. For example, deletion of a proposition node must delete all associative and speculative links to and from it. Similarly, deletion of an elaborative link must delete the footnote (a detail node) related to another detail node. Thus, the delete operation must behave differently based on whether the object is a node or a link. Similarly, a search operation can behave differently for different kinds of objects. Generic actions can also include the ability to create, edit, duplicate, or delete templates. Duplication of a template involves creating empty documents or nodes and the links or link sets associated with them.

Explicit Actions

Explicit actions are those which require an explicit qualifier or a modifier. The list operation is an explicit action since it requires the type of an object or other information. The result of listing all detail nodes can be a list in short form with object names or identifiers. A slightly informative version can be a preview of object names with all links to and from them and all nodes connected to them. A more complete explicit function can be the listing of nodes with their contents and all other nodes connected to them. The index operation can be provided by associative links in this framework. Explicit actions on a template can include the ability to add contents to empty documents, listing templates and their constituent documents and links, looking at an overview of the template, accessing a template by its type ("get a copy of the planning template") etc.

Control Functions

Control functions provide the ability to zoom into a subset of the hypertext network, forward and backward navigation through the web, provide overview maps, roam and zoom techniques, paths, trails etc. Control actions on a template can include displaying an overview of the template, zooming into specific link sets or webs (or "specific subgraphs" ) and looking at the contents of documents.


Hypermedia structures and systems assignment by Mark de Haas (0481832)