Wednesday, August 23, 2017

Lists and limitations

There are several things that Wikipedia does that you wouldn't necessarily guess just from a description like "online, world-editable encyclopedia."  One of my favorites is that tends to accumulate lists.  All kinds of lists.  List of bridges.  List of Eastenders characters.  List of enzymes.  List of Russian poets.  List of screw drives.  List of numbers (always room for one more).  List of presidents of Brazil.  List of fictional primates.  List of fires.  And, of course, List of lists of lists.

Honestly, part of the attraction is the sheer fun of seeing just what sorts of things people have seen, but there's a more serious point, too.   Our brains are subject to all sorts of biases that lead us to remember things selectively.  We tend remember things by their impact.  We remember more recent things better than less recent things (though we also tend to remember the beginning of a list of things better than the middle).  We remember things that we encounter more than similar things we don't.  We tend to remember things that have stressful emotional associations, and so forth.  In fact, there's a great list of these biases on Wikipedia.

One antidote to our natural biases is to lay out all the information in one place, for example, in a list.

To take a random example, what's the largest city in the US, meaning the one with the most area?  I've spent some time in LA, and I'd think that it, or one of its suburbs, must be pretty large.  Let's check the List of US Cities by Area.  And the winner is ... Sitka, Alaska, at 7434 sq km (2870 sq mi), population 8881.  Next on the list are Juneau, Wrangell and Anchorage, all in Alaska.

None of these is what we'd think of a a "big city", however large the city limits might be.  In fact, all of these are consolidated city/counties, and it's not surprising that counties in Alaska would be on the large side.  Likewise for Anaconda and Butte, both in Montana, a little farther down the list.  The first physically large city with a large population is number five: Jacksonville, Florida, area 1935 sq km (747 sq mi), population 821,784 (though Anchorage is over 200 thousand).  The first with a population over a million is Houston, Texas, area 1553 sq km (600 sq mi), population 2,099,451.

The next large cities with over a million are Phoenix and ... oh, there's LA at number 12.  Interestingly, New York, New York, which I tend to think of as the prototypical "lots of people packed into not much space", is number 24 on the list, between Kansas City, Missouri (Kansas City, Kansas is considerably smaller in both area and population), and Augusta, Georgia.

If all this matches up with your preconceptions, congratulations, your preconceptions are better than mine.

Or suppose there's been a major flood in your area (and, of course, I hope there hasn't).  Seems like it's happening more and more around the world?  Is it? Well, one way to find out would be to look at the List of Floods.  And, indeed, it looks like there have been many more in this century than before.  In fact, in the 1990s, the list shifts from decade-by-decade to year by year.

But that's not really right.  We've just gotten better at reporting them, and more recently-reported events might be easier to link to on Wikipedia.  So there are limits.  In this case, there's a clear sampling bias (I wouldn't quite call it recency bias, since that has to do with an individual's memory.

Maybe I'll just go back to browsing the List of images on the cover of Sgt. Pepper's Lonely Hearts Club Band.  Interesting bunch, that lot.

1 comment:

earl said...

Next to last para needs a ).