Path: utzoo!attcan!uunet!lll-winken!brutus.cs.uiuc.edu!tut.cis.ohio-state.edu!network!ucsd!cogsci!norman From: norman@cogsci.ucsd.EDU (Donald A Norman-UCSD Cog Sci Dept) Newsgroups: comp.edu Subject: Re: What to know & universal icons Message-ID: <767@cogsci.ucsd.EDU> Date: 24 Aug 89 17:15:14 GMT References: <56543@aerospace.AERO.ORG> <19238@mimsy.UUCP> <9059@eerie.acsu.Buffalo.EDU> Reply-To: norman@cogsci.UUCP (Donald A Norman-UCSD Cog Sci Dept) Organization: UC San Diego Department of Cognitive Science Lines: 60 I suspect there is no such thing as a universal icon, and for a simple reason: The development of signs and symbols is a critical and difficult evolutionary step. Only humans seem to have made the step to symbols, and even with humans, the development of even such simple signs/symbols as tally marks for indicating amount (pebbles to indicate amunt of animals, or notches in a stick) came rather late -- thousands (tens of thousands -- hundreds of thousands -- of years after the evolution of our species. If things were "obvious" they wouldn't have taken so long. (Simple enumeration schemes such as pebbles and marks appears to be the very first use of symbols, predating drawings. Enumeration (which is simpler than counting) also appears to be the forerunner of written language.) My colleague (Ed Hutchins -- an anthropologist before he put on his cognitive science uniform) and I argued in a paper that arrowheads were <> conventions of direction, not understood by all cultures. ---- The remark that arrows pointing upward mean forward, except when overhead in France, where they point down to mean frontwards is probably the correct way. I recently was sent a pile of papers on direction giving, including some by one of the originator of this debate, David Mark. That is simply a coincidence. But one of the papers was by Roger Shepard and Shelly Hurwitz: Shepard, R.N., & Hurwitz, S. (1984). Upward direction, mental rotation, and discrimination of left and right turns in maps. Cognition, 18, 161-193. Shepard and Hurwitz argue that "because our standard viewpoint is somewhat elevated above the generally horizontal surface of the ground, two points (A and B) on a path leading away in front of us project onto an intervening vertical plane with the farther point B, above the nearer point A. ... Thus, there is ... a natural correspondence between the forward direction ... and the upward direction" Following that simple principle, if a vertical arrow is below the horizon, up means forward, but if it is above the horizon, up means backward and down means forard. So the French got it right. Which also means that even such a thing as an arrow that means direction has to be interpreted relative to the observer's point of view, so it can't be "universal." (Shepard and Hurwitz also discuss the standard mirror-reversing problem (I wouold tell you the page number but my Xerographic copy doesn't have any), but I will pass on discussing this old, old problem.) Don Norman INTERNET: dnorman@ucsd.edu Department of Cognitive Science D-015 BITNET: dnorman@ucsd University of California, San Diego AppleLink: D.NORMAN La Jolla, California 92093 USA [e-mail paths often fail: please give postal address and full e-mail path.]