vocabulary seems to be fragmenting, modern times. I have picked up many words from various jobs and studies over the years, that I have never encountered elsewhere - if some test compiler happens to have spent time on a sailing boat or in a machine shop, working as a carpenter or insurance underwriter or railroad engineer, their compilation might be affected significantly. Common vocabulary might be shrinking, at the same time each individual vocabulary is increasing on average.
This is just another phenomenon caused by the march of civilization. Back in the days when more than 99% of the human population were farmers (which wasn't that long ago, it was still around 97% in the late 19th century), everybody had pretty much the same vocabulary. Variances from region to region would concentrate in the category of nouns: different plants, animals, weather, geographical features, etc. And since each region had its own language (and still does although the regions are larger), there were probably very few words that were not universal throughout one language community.
Today (in the developed nations) only 3% of the population are farmers. The other 97% of us have jobs in myriad other industries and professions. Each one has its own lexicon, so of course people who work in a drywall factory know words that people who work in an upholstery shop, a real estate brokerage, an auto repair shop, a stock exchange or a hospital would never have learned. Even farmers have a much larger, more specialized vocabulary then their forebears, since the reason so few people can now feed so many is that their jobs have been leveraged by technology like everyone else's--from the domesticated draft animal to the iron plow to the cotton gin to the tractor to vaccines to genetic engineering.
The evolution of civilization has broken down the old tribal boundaries between communities. Even we old folks can see the inevitable one-world-civilization in those tiny windows on our cellphones--the real-time image of a young lady shot down in the street in a country we claim we don't even like very much made us cry and write songs about her because dammit she didn't look much different from our own grandchildren. But instead it's creating new boundaries between
virtual communities that we create consciously: professions, hobbies, sports fans, tastes in entertainment, politics, religion. Each one has its own set of words.
The spread of literacy, which was limited to priests, aristocrats and their subsidized scholars before the invention of the printing press, brings us all in touch routinely with new words. This has vastly expanded our
passive vocabulary (words we understand) well beyond our
active vocabulary (words we use in our own speech or writing).
Vocabulary tests obviously only test passive vocabulary.
Nonetheless, I felt that the people who created the one I linked to in this thread had done a very good job of dealing with jargon. I'd say there's a core vocabulary of words that anyone might encounter in an average day of reading the popular press and browsing the internet. Beyond that there are a few erudite or jargon words, which I assume were chosen evenly from a wide variety of professions, hobbies, academic specialties, etc. I recognized a couple from biology and other disciplines in which I work or dabble, so it's reasonable to assume that they included a wide spectrum and don't give more credit to computer programmers than to sociologists.
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