8.2 Guided Tours and Tabletops in NoteCards

NoteCards is one of the preeminent research hypertext systems that was developed from 1985 to 1988 at XEROX PARC [Hal86]. NoteCards pioneered concepts such as typed links (figure I.27), and graphical overview maps of hypertext documents (figure I.28).

Figure I.27 Visual representation of different
links from and to a NoteCards node
http://vertex.cs.bsu.edu/colloquim/link.gif

Figure I.28 Graphical overview map of the linking structure of a
NoteCards hyperdocument http://vertex.cs.bsu.edu/colloquim/browser.gif

To allow sequentialization and easier access to complex hypertext documents, NoteCards offers to the author guided tours and tabletops [Tri88]. Tabletops are a mechanism for defining the layout of a set of NoteCards cards on the screen. A tabletop contains a set of cards, their screen positions, scrolled locations, size and overlapping arrangements. Fig. I.29 shows an exemplary tabletop, specifying an arrangement of NoteCards cards on the screen. A "tabletops" card contains links to other tabletops and thus defines a sequence of screen snapshots.

Figure I.29 Exemplary NoteCards tabletop
http://vertex.cs.bsu.edu/colloquim/ref.gif

The guided tour facility is based on the tabletops concept. It offers a graphic interface to link a network of tabletops. To create a new guided tour, authors normally create an empty guided tour card, and then add new tabletops by placing the appropriate icon on the guided tour card using an attached menu (figure I.30).

Figure I.30 A mock-up of a NoteCards guided tour card

To operate a guided tour, the reader uses the five buttons attached to the guided tour card. The purpose of a guided tour is to give to somebody not already familiar with the NoteCards document an overview of the material contained in it.

Marshall and Irish used Trigg's guided tours and tabletops to make their hypertext documents more intelligible to the reader [Mar89]. They employ a three step process. First, they enforce a consistent screen layout by using a set of predefined tabletops. Second, they additionally mark the tabletops with large, bold arrows to guide the reading direction of the user. Third, they link the tabletops to build the guided tour.

Guided tours and tabletops offer a simple way to give the reader a quick overview of a hyperdocument. They have to be built manually by the document author and demand detailed knowledge about the original document. They are static in that they are based on static links. The next section illustrates a more flexible way to build guided tours or paths using a scripting language.