The importance of algorithms in our lives today cannot be overstated. They are used virtually everywhere, from financial institutions to dating sites. But some algorithms shape and control our world more than others — and these ten are the most significant.
Just a quick refresher before we get started. Though there's no formal definition, computer scientists describe algorithms as a set of rules that define a sequence of operations. They're a series of instructions that tell a computer how it's supposed to solve a problem or achieve a certain goal. A good way to think of algorithms is by visualizing a flowchart.
1. Google Search
There was a time not too long ago when search engines battled it out for Internet supremacy. But along came Google and its innovative PageRank algorithm.
Today, Google accounts for 66.7% of the U.S. market share in core search, followed by Microsoft (18.1%), Yahoo (11.2%), Ask (2.6%), and AOL (1.4%). Google now dominates the market to the point where we don't even question it anymore; for many of us, it's our primary avenue of entry into the Internet.
PageRank works in conjunction with automated programs called spiders or crawlers, and a large index of keywords and their locations. The algorithm works by evaluating the number and quality of links to a page to get a rough estimate of how important the website is. The basic idea is that the more important or worthwhile websites are likely to receive more links from other websites. It's basically a popularity contest. In addition to this, the PageRank algorithm considers the frequency and location of keywords within a web page and how long the web page has existed.
2. Facebook's News Feed
As much as we may be loathe to admit it, the Facebook News Feed is where many of us love to waste our time. And unless your preferences are set show all the activities and updates of all your friends in chronological order, you're viewing a pre-determined selection of items that Facebook's algorithms have chosen just for you.
To calculate which content is most interesting, it considers several factors, such as the number of comments, who posted the story (yes, there's an internal ranking of "popular" people and those with whom you interact with the most), and what type of post it is (e.g. photo, video, status, update, etc.).
3. OKCupid Date Matching
Online dating is now a $2 billion industry. Thanks to the growth of such sites as Match.com, eHarmony, and OKCupid, the industry has expanded at 3.5% a year since 2008. Analysts expect this acceleration to continue over the next five years — and for good reason: It's an extremely effective way for couples to meet. Not only do dating sites result in more successful marriages, they do an excellent job matching prospective couples based on their various preferences and tendencies. And of course, all this matching is done by algorithms.