User Interface Metaphors Rainer Brockerhoff Abstract: Cognitive science is taking a revolutionary turn, away from abstract theories of the mind and towards a recognition of the essentially embodied nature of human thought, processing concepts in terms of conceptual metaphors. Computer user inter- faces, as complex metaphors in their own right, can now be discussed in terms of their relationship to our basic cognitive processes. As a rule, user interface metaphors that are solidly grounded in physical concepts and experiences may be considered more “intuitive”. A Brief Introduction, Inter- · We can know our own minds by in- spersed with Warnings, Dis- trospection, claimers, Apologies, and · Most of our thinking about the Miscellaneous Weaseling world is literal, and Up to a few decades ago, western phi- · Reason is disembodied and univer- losophers and scientists have been sal, working from a foundation which has usually been considered too obvious to However, PitF demonstrates empirically state explicitly; namely, that reason is an that: abstract, disembodied, universal and purely formal entity. This underlying · Most thought is unconscious. What assumption is so pervasive that I at first is available to introspection is a very wrote “philosophy and science” instead small portion of the mind’s proc- of “philosophers and scientists”! esses. A recent revolution in cognitive science · Abstract concepts are mostly meta- has pulled the carpet out from under phorical. Basic metaphors derived this assumption. I hasten to add that my from bodily conditions and experi- academic qualifications are insufficient ences are necessary to form even a to do more than give a brief summation simple thought. of my understanding of the scholarly works cited at the end of this paper. · Mind is embodied. The structure of Furthermore, many sectors of the scien- our thought requires a body. tific and philosophical establishments appear to remain unconvinced of the You may question the use of the word arguments exposed therein. “metaphor”, since it is a common mis- conception that this refers only to liter- My main reference here is “Philosophy ary analogies; however, contemporary in the Flesh” 1, by George Lakoff and linguists have considerably enlarged the Mark Johnson, which I will irreverently meaning of “metaphor” 2,3,4,5. For our refer to as “PitF”. Any inaccuracies in purposes, we can consider a metaphor transcription and interpretation are my to be a “mapping” function that projects own. the structure of some source domain — usually a basic bodily perception or The classical assumptions state categori- movement — onto a target domain (see cally that: Interface Metaphors – Page 1 the Lakoff & Nuñez paper for a more Hopefully you are now suitably cau- complete explanation). tioned in taking the following cum grano salis regarding my interpretation of the Grounding metaphors map common general theory, and sufficiently inter- physical experiences onto a target do- ested in considering how all this might main; examples would be “movements be applied to actual computer interfaces. are changes” (exemplified by the phrase “we came to an agreement”), and “time Finally Sort Of Getting to the is money” (“he invested much time on this paper”). Subject, and Some Historical Considerations There are also complex metaphors, which are higher order mappings of simpler To get myself back on more familiar metaphors, used to express complex ground, I’ll quote from John Lawler’s ideas, like “the mind is a machine” (“he 1987 lecture “Metaphors We Compute had a mental breakdown”), and linking By” 9. In the section “The Desktop: the metaphors which map different do- Computer is a Workplace”, he says: mains onto each other, like “the number line”, which maps arithmetic onto ge- We're all familiar with the Macintosh ometry. Both of these are used to ex- Desktop and its origins in the Xerox Star tending our metaphorical reach into and its copies in Windows, etc. And we've all had lots of discussions about how great regions that were not accessible to an advance it is in user interface design thought beforehand. (whether we believe that or not, there are enough folks who do to involve us in such It must be stressed that all these meta- discussions almost endlessly). You have to phors operate effortlessly and below the admire that kind of enthusiasm, and the level of conscious awareness. The defi- products that evoke it. Nevertheless, we've nitions and examples are simply surface not yet arrived at the perfect user interface. manifestations of metaphorical thought, the tip of the tip of the iceberg of the … I don't really see a great deal that can be mind. Any new metaphor we make up done about it, in fact, beyond making user consciously must use the mechanisms of interfaces as customizable and flexible as possible, and using a lot of synonyms our unconscious, everyday metaphor when designing them. The point I want to system; however, it seems that the ease make here is that diversity in personal of applying the new metaphor depends styles of information management is not enormously on the number and com- yet a well-known or -handled part of user plexity of levels separating it from the interface design. There's always a big grounding metaphors. problem with adaptation; either you have to adapt yourself to the design of the com- PitF, after a detailed explanation of puter (and you may not be able to do so these and other basic concepts of what usefully), or you have to adapt the com- the authors call “Second-generation puter to your own strategies (and this is a very difficult task at best). Mostly we try to cognitive science”, goes on to an analy- do both, with quite variable degrees of sis of the underlying metaphors of clas- success. sical and modern philosophical theories, with often surprising and profound re- At the time of Lawler’s lecture — he was sults. I also refer the interested reader to an early Mac enthusiast — the idea that other publications which apply this metaphors were useful for human- methodology to mathematics 6, arith- 7 8 computer interaction was already well- metic , politics and […]. established in the minds of Apple’s hu- man interface designers, and they of course were based on the ground- Interface Metaphors – Page 2 breaking concepts developed at Xerox ther along by brute-force techniques. PARC, and other research centers. Even And, of course, household robots are so, this appears to be the earliest aca- still as far off as they were in the 1960’s, demic reference to human-interface and machine translations by BabelFish metaphors outside of the computing and other efforts are the source of much field. merriment and derision in the Internet community. Before the appearance of the Graphical User Interface (GUI) and the invention At the same time that cognitive science of the mouse by Douglas Engelbart, the was making the leap from the “abstract basic metaphor for human-computer reason” to the “embodied mind” model, interaction was what Lawler defines as computer interfaces went graphical. “Computing is a linguistic activity”. Not Suddenly, computer users were no only were computer interfaces text- longer required to learn an abstract based and linear, but in both popular command language to operate a com- and technical views of the computer puter. Icons, graphical representations, knowing a “computer language” was point-and-click and copy-and-paste be- basic to interacting with a computer. came the paradigm of the computing From the 1950’s to mid-1970’s, operating experience. A parallel effort to apply and programming a computer were these concepts to programming has practically synonymous. been much less successful, at best re- sulting in better representation of high- In the same time frame, Noam Chom- level relationship in programming enti- sky’s models of generational syntax and ties, at worst spawning a whole genera- transformational grammar constituted tion of Visual Basic professional the orthodoxy of linguistic thought. amateurs. These ideas of, ultimately, reducing human language to abstract syntactic The success of the GUI was accompa- and semantic schemata ran parallel to nied by unsupported claims that such developments in computer science, interfaces were somehow more “intui- where more and more complicated tive”. My personal experience was that “languages” were devised, and in artifi- they were easily learned — at least by cial intelligence, where symbol ma- somebody already well versed in earlier nipulation and logical inference were technologies — but explanations about seen as the obvious way to model the why they were intuitive were not com- human mind. Philosophical reduction- pletely convincing. And as anybody ism seemed poised to conquer the who tried to teach an elderly relative to world. Household robots and machine use a word processor or e-mailer knows, translation were considered to be “just they’re not all that intuitive to layper- around the corner”… sons. Alas, it was not to be. Soon Chomsky’s Unfortunately after the comparatively disciples were scattered in wildly differ- sudden takeover of GUIs, no substantial ent directions in what are now termed refinements or new paradigms have ap- the “Linguistics Wars” 10. The two-level peared. Color, drag-and-drop, translu- syntax fiasco put an end to the com- cency, throbbing default buttons, and so plexification of computer languages forth are merely refinements but not (although the recent ANSI C++ stan- revolutionary developments. Three- dard’s complexity reminds me very un- dimensional interfaces and “Virtual Re- comfortably of the “Algol 68 Report”). ality” are still hampered by inadequate Artificial intelligence hit a conceptual hardware and lack of theoretical under- brick wall; in my opinion, the wall has pinnings. And, of course, there still are not been breached but only pushed far- many people who consider GUIs defi- Interface Metaphors – Page 3 cient in one way or another; for an ex- themselves, and invented to ease the tremely interesting and articulate argu- computer’s tasks instead of the user’s.