>However, I have done so based on simple observations of how people change >from old measures to metric units. If they use millimetres, the change is >smooth, rapid, and orderly; if they choose centimetres, the change is rough >(with much reverting backwards and converting to old measures), slow >(perhaps 50 years with centimetres as opposed to 50 weeks with millimetres), >and disorderly (characterised by bitter infighting between individuals and >between groups).
But there are many possible explanations for that. 1. Industries moving to millimeters have a need of higher precision. They are probably moving from fractions-of-inches to millimeters. They is a very large win for them, as they move from awkward fractions (usually with a base of 1/16 inch) to whole numbers with a greater precision of 1 mm. 2. Industries moving to centimeters probably aren't precision critical (e.g. clothing industry). Therefore they are moving probably from whole inches to whole centimeters, so the win isn't as great, and maybe it isn't enough to overcome intertia. 3. Some uses of sizes are much more isolated. For example, consider shoe sizes. It doesn't really matter if they are inches, centimeters, etc - they are simply size numbers. A person knows what his size is, and just looks for a match in his purchase. Changing the units doesn't offer any advantage, and the effort isn't worth the inconvenience. On the other hand, changing furniture sizes to metric might be useful if you have to calculate whether three diverse pieces will all fit along one wall (using millimeters is great for that, as it is all whole numbers; using fractions of inches is horrific). Once actual calculations are involved, metric offers a bigger win. 4. Things like clothing sizes have a somewhat emotional aspect. People don't like their waist measurements suddenly more than doubling :-), which can introduce consumer resistance. Anything to do with body measurement is always last to change (e.g. Australians still quoting their height in feet and inches, whereas they often quote their weight in kilograms, which are numerically less than the equivalent pounds). Therefore using millimeters rather than centimeters in those industries would be even more likely to incur resistance. Having said this, I would concede that millimeters are much more likely to be useful than centimeters, and that *if forced to make a choice* I would choose the former. My contention is that just because millimeters are the appropriate choice for the vast majority of industries, it shouldn't be forced on the few for which it isn't. ------------------------------------------------------------------- Tom Wade | EMail: tee dot wade at eurokom dot ie EuroKom | X400: g=tom;s=wade;o=eurokom;p=eurokom; Unit A2 | a=eirmail400;c=ie Nutgrove Office Park | Tel: +353 (1) 296-9696 Rathfarnham | Fax: +353 (1) 296-9697 Dublin 14 | Disclaimer: This is not a disclaimer Ireland | Tip: "Friends don't let friends do Unix !"
