Design Considerations for Spatial Metaphors
reflections on the evolution of viewpoint transportation systems
Heiner Benking and Anthony Judge
Position Paper acm-ECHT Conference, Edinburgh 18-23 September 1994
This note assumes that the future evolution of the use of spatial metaphors in interface design will not be focused on any single metaphor. For a variety of reasons there is a need for environments permitting user-choice, or AI-selection, of metaphors through which information is communicated in either direction. The following remarks highlight some of the issues relating to this evolution.
1. Classes of metaphors
There is a need to distinguish classes of metaphors offering different advantages and disadvantages. Typically they would include: geometric forms (cube, sphere, polyhedra in general), artificial forms (townscapes, house, room), natural forms (landscape, trees, etc.), systemic structures (highway systems, pathways, flow systems), dynamic systems (atomic, molecular, planetary, galactic systems), traditional symbol systems (mandalas, sand paint ings, etc.).
Of special interest are those sets of metaphors which permit inter-transformation with minimal loss of conceptual integrity (in terms of maintaining relationships between data referents). This function is important with respect to user learning, user preferences for information organisation and cultural biases and preferences in information organisation. It is however equally important as a way of handling different levels of complexity.
With information beyond a certain degree of complexity it is questionable whether any single metaphor is adequate as an interface for adequate comprehension. This is best exemplified by the wave/particle metaphors used to comprehend fundamental physical systems. There is therefore the interesting possibility, that some complex systems may only be adequately comprehended through three or more complementary metaphors. This consideration also relates to psychological type-theory by which the number of types distinguished may correspond to the number of metaphors appropriate for comprehension (The astrological types are perhaps an extreme example).
4. Relevance of morphing techniques
It is interesting that the debate on metaphors has proceeded independently from the development of morphing. The reason may lie in the emphasis on the necessarily visual (superficial) features of the images which are morphed. These have not yet been considered as ways of carrying information as is the case with the metaphors considered earlier. There is no reason why users should not be free to distort any initial metaphor into some preferred form. Morphing can also be used by the user to reconfigure information in terms of complementary metaphors.
5. Alternation and perspective
There are learnings from the use of two eyes to obtain a sense of perspective. It is equally desirable to understand the use of metaphors in terms of the alternation between perspectives which provide a sense of depth that would otherwise be unavailable. Such 'depth' is distinct from that obtainable from any 3-D metaphor which although it offers depth is cognitively not as significant as that offered from the cognitive integration of two contrasting metaphors. Such 'depth is only achievable by alternation between metaphorical interfaces (as the wave/particle example suggests).
6. Metaphoric library
There is merit in considering the possibility of a library of metaphors analogous to the 'libraries' available in software packages. Such a library might contain many of the metaphors noted above. A stage may be envisaged in which metaphor libraries might become equivalent to figures as in drawing packages. These could then be seen as archetype libraries to trigger ideas in brain-(quickstorming) processes.
7. Pattern fitting
Of great interest is the possibility of using algorithms to fit data to spatial metaphors. Through this function the user would be presented with a selected sub-set of metaphors to which the information can be usefully fitted.In its simplest form this would be of value in interrelating key concepts in the outcome of conferences. Typically the intellectual product of such events (e.g. UN Conference on Environment and Development, Rio de Janeiro, 1992) takes the form of complex declarations and programmes (e.g. Agenda 21). The challenge is to configure the conceptual elements into a globally comprehensible form. This is necessary to counteract the tendency to generate an asymmetric agglomeration of elements (of which Agenda 21 is a typical example). In addition to its mnemonic function, a metaphoric framework can then highlight possible missing elements as well as suggesting ways of understanding inter esting functional relationships between such elements. In this sense a metaphoric framework can be used to 'challenge' any conventional legalistic structuring of academic or policy conferences. Such feedback can suggest the use of alternative metaphors.
8. Sterile metaphors
It is useful to treat the use of metaphors 'self-reflexively'. This can best be illustrated by the many proposed architectural and landscape metaphors. Some of them appear to suffer from inadequacies analogous to those noted by critics of sterile architecture and city-scapes (sterile or criminal downtown areas) - to which environmentalists have proposed many alternatives.
9. Knowledge spaces and navigation
An optimal metaphor for storing and exploring data and knowledge are scapes (deep structured spaces) as found in Nature. We can define knowledge topologies, even a panorama, ranging from particles, areas, bodies, scapes to a Gestalt. We gain by expanding the perspective by agreeing on views in given frames (superstructures) by the mind's eye.
In such a virtual space, previously only available in an aperspective mode, we can make sense by locating and interpreting virtual entities and objects. To immerse or 'dive' into such a topology of information, maybe seen as a multi-story information warehouse, needs making use of teh third dimension and an internal deep order. We need to navigate in and between bodies of expertise (domains) and not restrict ourselves to the surface, avoiding depth and hidden or invisible structures on other levels. Learning to explore the virtual space like children explore the physical space makes fun and is the real challenge. The challenge to make use of cyberspace to escape, but to make sense by exploring new domains.
The metaphor should than take the form of Nature Space, which has features of infolded (or fractal) ordering to carry other levels of information. Much thought has been given tin the 1960s to such a Conceptual Superstructure concept by Douglas Engelbart ( Augmenting the human intellect: A conceptual framework).
10. Piggy-backing on drawing packages
Aspects of what is advocated above can be envisaged as an adaptation of certain kinds of drawing packages. The requirement is that it be possible to attach user information to any feature of a drawn object. This function is to be distinguished from conventional labelling. Rather each feature effectively allows the user to open a box into which information may be put. The box can than be hidden until clicked open. Any object drawn or retrieved from a library are then effectively, clusters of information, boxes or drawers which may or may not be filled. If the package is used to select a metaphor object to cluster and hold a set and subsets of user information elements (statements and relationships between them, images, etc.), the features might be differently coloured if filled in this way. Equally if information was independently acquired and particular categories (e.g. accumulation of transactions entered into the information databases by other external parties) the colour might be used to signal the quantity of information attached to any feature of the metaphoric view on that database.
Within such a context conventional zooming could be used to expose finer levels of structure that could be used in the same way as hangars for more detailed clusters of information. The emphasis here is that a drawing package (or some drawing packages) could probably made 'intelligent' with relatively little effort. One approach might simply be to attach a record ID field to every such drawn feature. The ID would then point to user information in a related datafile. Refinements might enable a number of different figures from the library to have the same set of record IDs plugged into them. The user then has access to different visual configurations of teh same information. Things become features, possibly to the size of a palace. Alternatively a user could select a 'palace' from the library and furnish/decorate it with information (as pointers to an appropriate file). The palace could be 'remodelled' at any time, gardens, and animated features (animals, servants, etc.) could possibly be added. Such an approach, whether applied to personal interest information or to that relating to an official function, would then allow different users to 'introduce' themselves through opening selected parts of the customised metaphor to each other, namely 'walk-through' facilities.
This approach is clearly related to the potential or virtual reality techniques. A workgroup might then take thevisual form of a cluster of houses linked by pathways (with gates, secret doors, etc.) which those involved might be constantly redesigning. Some might prefer the additional feature of 'gateways' to alternative realities or spaces where the same information was configured otherwise.
11. Mnemonic advantages
It is appropriate to note that mnemonics was a highly developed art prior to the widespread availability of paper - and especially to facilitate the task of orators of renown. A major feature of this art was the distribution of information onto visual surfaces which could subsequently, be walked through and interrogated for the next points in an argument. Typical surfaces were so-called 'memory palaces' and garden scapes (mandalas should also be seen in this light). It can now be argued that there is an analogous need for such visual metaphors to enable individuals to handle information overload and retain some control over the information they endeavour to possess. Spatial metaphors can be seen as vital to retaining posses sion of information and avoiding 'memory leakage' or the effective 'dismemberment' of one's information space.
12. Intellectual property
It is possible that intellectual 'property' may come to be usefully defined in terms of spatial metaphors. Access to them, in the case of corporations, may be jealously guarded since they would then effectively define the corporations self-identity.
this work is licenced under a creative commons licence.