Monday, January 30, 2012

Note on Wayfinding

I left the autumn discussion on Wayfinding unresolved as to whether full overhead mapping was at all hardwired or merely a recent variant of sense of direction (as opposed to landmark navigation.) I had felt strongly there must be something of a heritable spatial ability, but the evidence for it was elusive. Dead reckoning seemed to have more experimental evidence behind it. Jennings makes several references in Maphead to navigating as if from above eye level, but not looking down at a flat 90 degrees as on a map.

Something between 10 and 30 degrees seems to come automatically to some folks when picturing medium-distance navigation, rather like an actual bird’s-eye view, elevated but looking forward, rather than what we usually call a bird’s-eye view. I don’t know of any research on it, but it seems likely. It would be the view one would have from a mountain or rise of land, or even from climbing a tree. Extrapolating that to picturing an area in one’s head, even things which could not actually be seen from any earthly point, seems entirely plausible. A slight angle of elevation would be more closely related to dead reckoning and compass orientation, but once the concept of getting off the ground was in place, once that seal was broken, exagerrating it to full 90 degree overhead doesn’t seem so odd.


Anonymous said...

Sorta-related: commercial GPS devices normally have two ways to toggle the display. One is straight overhead (usually they call this "2D" display, which can also usually be adjusted to be north-up or direction-of-travel-up). The other is a view from an imaginary point perhaps 100ft. above your current location, facing the direction you are traveling (called "3D").

I always notice this, because I prefer the "3D" display, and if I do use the "2D" display, I will usually set it to direction-of-travel-up. My husband HATES this, and will only use the "2D", north-up display. At first, I thought it was just a peeve. Then I realized that he gets seriously disoriented if he sees a map that isn't a straight-overhead, north-up view.

I think it's because we are using the GPS in very different ways. I am looking for the information I'd need for the next turn, primarily, and the 3D view gives me that-- but with a higher viewpoint, so that I see more of the surrounding area that might impact my choices (say, whether to use the far left or near left turn lane at the next intersection). You described this as "landmark navigation". My husband is drawing a line in general space, and having his reference point (true north) constantly shifting on the display is intensely distracting.

I shift to the 2D north-up display if I am looking at the route as a whole, or deciding between two different routes. He does that sort of navigating 100% of the time, whereas I do that sort usually only at the beginning of any given trip, or when I have to do a major detour. I also want the straight-overhead view when I'm new to an area, and I'm trying to get accustomed to where things are (not just how to get from point A to B, but a general knowledge about where A and B are, and thus where C, D and E lie in relation to them.) So, it's clear to me now that I have two maps in my mind (bird's eye and satellite view, if you will), whereas my husband only seems to have one useful map.

Texan99 said...

I was in San Antonio today, trying to get directions from a clerk in one store to another store a couple of miles away. He really wanted to give me the directions in dead reckoning. I really wanted him to help me understand what kind of map I should be drawing in my head. I eventually got him to switch over to compass directions.

Driving home later, I found myself in a deep rural patch, where the small road I had expected to take was completely shut down for repairs. It was quite dark by this time, with fog rolling in. Yow! Good thing I had a GPS on my phone, particularly as I messed up the detour somehow and found myself on a very long dirt road out in some fields, which luckily for me didn't dead end out there. I eventually found my way back to the original road past the construction. GPS is great stuff. You get a map as well as a little "you are here" blog and an clear sense of what direction you're going in. If I'd had to rely on dead reckoning, I guess I'd have headed for the lights on the horizon knowing I'd eventually hit the Gulf of Mexico. It's so flat here that you'd think navigation would be easy, but you still have to worry about the rivers and bays, not to mention the ranches with no through roads.