Frysinger's post is genuinely insightful. It reminds me of something I experienced years ago.
I was driving somewhere with my four-year-old daughter on the seat next to me. Waiting at a traffic light, I thought it would be a good moment to start teaching her the rudiments of traffic safety. I asked her how many colors there were on the traffic light. She watched it change and finally answered "four." "Really?" I answered indulgently. "What are they?" "Red, yellow, green," she said, "and black." I was thunderstruck. (Never mind the physics that black is the absence of color. Every child with a box of crayons knows that black is a color.) Of course she was right. I had never noticed black because it was not meaningful. It did not mean stop or go. People need preconceptions, a frame of reference if you will, in order to perceive - to gather and sort data. The principle applies widely in human cognition and behavior. ------ On 11/25/07 2:32 PM, "James Frysinger" <[EMAIL PROTECTED]> wrote: > Ezra and all, > > Countless experiments have shown that people tend to see what they are > looking for. Let's imagine tourists in Burma who are trying to fend for > their needs. They are going to be on the lookout for something that > seems familiar and that speaks to them in a language they understand. If > they are typical American tourists they can tell you of the many places > where they saw familiar units being used and that they don't recall any > other units. If they are tourists from almost any other country, they > will assure you that they saw zillions of metric indications and few, if > any, non-metric units. > > We see this often in the U.S. I've had folks swear up and down that they > never see metric units used anywhere and then I have them read the > contents indication on their can of pop or the nutrition information on > their snack package. Indeed, sometimes I've asked people to read me what > the label claims to be on the 500 mL bottle of water and they just read > me the number of pints and floozies shown in parentheses, skipping right > over the "500 mL" that appears first. Yes, they realize that those > "other" units are metric. However they didn't "see" them until then and > if they had seen them earlier it didn't register long enough to create a > memory of that. > > I've had beginning students in Physics who, during our first lab which > is on metric unit familiarization, would wave their rulers in the air > and proudly tell us that the college bookstore sells only "inch rulers". > I would ask them to tell me what's on the other edge of that ruler and > they are amazed at what suddenly appears there--namely centimeters. They > truly had not "noticed" the metric scale on those rulers. > > I'm on the lookout for metric usage, so I see it quite often in the U.S. > Pat Naughtin has seen them here quite often as well, but he's a "metric > tourist" over here, so his eye gravitates to units with which he's > familiar. Non-metric people who live here rarely "see" what we see. > Actually they do see those metric units, but they don't notice them and > the experience does not register. > > Jim >
