My favorite programming assignment in school was a Scheme implementation of the "stable marriage algorithm".<p>"Let's assume, for the sake of an argument, that you are a village matchmaker given the task of marrying
100 men and 100 women. Each of the men has ranked the women from 1 to 100 in the order of his preference;
each woman, not to be outdone, has similarly ranked the 100 men...Rather than insist that everyone get their first choice, you are instead charged with creating 100 stable
marriages. A set of marriages is said to be stable if there exists no man m and woman w such that m likes
w better than his wife, and w likes m better than her husband. The notion is called "stability" as m's and
w's marriages are unstable, since (albeit sordid and tawdry) m and w could optimize their sorry lot in life
by leaving their mates and running off together."<p>Non-PDF link:
<a href="http://64.233.169.104/search?q=cache:abZ7sCKHUmYJ:www.cs.brandeis.edu/~mairson/Courses/cs21b/marry.pdf&hl=en&ct=clnk&cd=1&gl=us" rel="nofollow">http://64.233.169.104/search?q=cache:abZ7sCKHUmYJ:www.cs.bra...</a><p>Not the same as algorithms discussed in the article but fun and interesting.
eHarmony isn't successful because of the matching algorithm. eHarmony is successful because of the steep barriers to entry, perception of safety and privacy, its ability to attract women to the site, the rate at which they regulate match delivery, and the guided communication process.<p>The result is that you don't waste much time browsing profiles. You don't waste time trying to filter out spammers. You don't waste time coming up with clever pick-up lines. You don't get pestered by matches you close.<p>The matching algorithm definitely matters, but it's mostly a red herring. If I were eHarmony, I'd be far more worried about my terrible user interface than the matching algorithm.
e-harmony is very similar to my start up. We operate in Mexico somoscompatibles.com (we are compatible). Our approach is to find personalities and rate how similar they are. I tried eharmony for several months and I don't think they really have a great algorithm, they just make it easier for you to know some people that are somewhat similar to you.
By having an exclusionary policy, eHarmony appears to be attempting to improve their results by keeping people out that are less likely to fit their algorithm.<p>I'm impressed that they've hired so many PhDs, but on the other hand, I don't believe that having the computer match you is going to be very successful overall.
Last year I did a lot of work under contract to build a machine learning based data web site where users would vote on people and the ML part would build up a model of what they were looking for. Unfortunatly, the site has not yet released because of trouble finding a good Javascript person to work on bits of the UI.
does eHarmony still refuse to match a huge chunk of people? i've heard about 20% or so are unmatched or something like that. which interestingly almost coincides with the commonness of a certain range of personality types in the Jungian theories<p>speaking of which, i'm surprised Jungian theories aren't more popular. there are specific type pairings which go very well together -- like the people you meet that you just "click" with. well, that clicking can be seen clearly in the theories by the way the types are described
eHarmony's ability to market itself/word-of-mouth is impressive. My relatives/parents are like broken record players 'You know, Roy met his wife through eHarmony...' My friend Mike met his wife through eH as well - I remember him complaining about how long it took to answer the questionnaire set.