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Collective knowledge

In 1857, a group of British intellectuals decided to compile a new English dictionary with a comprehensive set of words, definitions, and usages. They put out a call for volunteers to submit words from books in their libraries and eventually received more than 2 million word references.1
Photo of a box filled with slips of paper with words and sentences written on them.
A box of word suggestions sent to the Oxford English Dictionary team. Image source: Media specialist
In 1928, the first edition of the Oxford English Dictionary was finally complete and contained over 400,000 words and phrases.2
Photo of 10 books, each with a different volume number and letter range printed on the side of the book.
Volumes covering letters B - N from the first edition with its original title, "New English Dictionary on Historical Principles". Image source: Liz West
The creators of that dictionary had an important insight: there's no one person that knows every bit of information, but when we combine knowledge from many people, we can develop impressively comprehensive collections of knowledge.
A diagram representing the crowdsourcing of knowledge from multiple people into a collective knowledge base. Shows six icons of people next to a page of text, with arrows flowing from the pages of text into an entire book.

Crowdsourced knowledge in the digital age

Thanks to computers and the Internet, creating a shared knowledge base is much easier these days than it was in the 1800s. When someone contributes information, the computer can store it in a database and make it easy to sort, search, and edit. The community of contributors can sort through the database to keep the highest quality information, and computer programmers can help by adding reputation systems, voting algorithms, and spam detection.
Wikipedia is a great modern example of a crowd-sourced knowledge base. You've probably run into a Wikipedia article if you've ever searched for knowledge online. With nearly a billion edits since its inception and over 36 million registered users, Wikipedia is collecting the wisdom of a very large crowd.3
I'm one of the millions in that crowd, since I made eight edits this year while working on AP CSP articles:
Screenshot of list
A listing of edits, with timestamps and edit size for each.
The fact that anyone can contribute—and have their edits appear instantly—is both a blessing and a curse.
Wikipedia intentionally lowered the barrier to contribution with the hope that they could create an encyclopedia that'd cover every topic worthy of an article, and it's well on its way to that goal. In June 2019, there were 5.9 million articles in the English Wikipedia and around 20,000 new articles added each month. In print form, that would be equivalent to 2,822 volumes of the Encyclopedia Brittanica:
Illustration of 2,822 books in 15 bookcases.

The risks of crowdsourced knowledge

Can a volunteer community really ensure the accuracy of millions of articles? They can try, but realistically, they can't. You might have the misfortune of reading an article right after a troll made a malicious edit, a spammer plugged their company, or well-meaning but misinformed person introduced an inaccuracy.
During a lunar eclipse in 2011, one vandal made this edit:
Screenshot of first sentence from Wikipedia article on Lunar eclipse, with text "A lunar eclipse is when the moon turns black and explodes, releasing a poisonous gas, killing all of humanity."
To combat the effects of errors, Wikipedia encourages citations for every bit of knowledge added and advises caution in using Wikipedia as a primary source for research.
Wikipedia also suffers from another drawback of a crowd-sourced community: a lack of diversity. In theory, a website can bring in a wide range of people, since the web is open and global. Yet in reality, the contributors to Wikipedia don't mirror the readers of Wikipedia. A 2013 study found that while 47% of Wikipedia readers are female, 84% of Wikipedia editors are male.4 This imbalance may skew the topics covered on Wikipedia and the way they're presented.
🤔 Consider other crowd-sourced knowledge bases that you use, such as Q&A websites and discussion forums. How trustworthy is the knowledge accumulated on those sites? In what ways might that knowledge be biased by the bias of the contributors? Is the overall increase in new knowledge worth the possible inaccuracies and bias?

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