Matching

To power their complex matching algorithms, eHarmony relies on four database and data warehousing products.

• The very popular and open source MySQL database server.
• Oracle Database.
• Data warehousing appliances from Netezza Inc.
• Hadoop, a open source data crunching application which divides work among a large number of computers.

eHarmony uses Orcale to do the initial matching after a new member signs up. For the behind the scenes processing, eHarmony uses a 50 node Hadoop cluster. Since moving to Hadoop, eHarmony has seen 4 to 6 times sped improvement in how long it takes to perform matching calculations on a large scale.

All this technology is controlled by eHarmony's main technical team, which includes 40 engineers based at the Los Angeles headquarters. eHarmony also has hired a number of development firms throughout Europe, which has doubled the number of engineers working for them.

To find out more about the technology that powers eHarmony, read ComputerWorld. For more on the dating site itself, check out some of our reviews of eHarmony.

Christine makes a good point in this article from the Palm Beach Post. Certain profile preferences on dating sites shouldn't be negotiable. This will differ from person to person but most singles would agree that their view on how much they want their potential partner drinking and/or smoking will not change, especially if the person says NEVER. Usually they have a very good reason.

In Christine's case she is a recovering alcoholic and she had told eHarmony that she didn't want a match who drinks. After only a few matches from eHarmony, she received an email from the dating site suggesting she widen her match preferences in regards to drinking, to someone who may have a drink at least once a week. Obviously this would not work for someone like Christine.

I think dating sites like eHarmony which are designed to match singles based on complex matching system need to take into account the deal breakers every person has when it comes to being partnered with someone. For me it is smoking, for someone one else it may be location or religion. eHarmony should realize asking someone to modify a matching preference which may be a core belief could lead to upset customers.

Two of OkCupid's co-founders, Chris Coyne and Christian Rudder (who met in a Harvard math dept.) created OkCupid's complex matching system, which they have coined the UberAlgorithm. The UberAlgorithm is all mathematics and essentially tracks the tests and quizs members take at OkCupid. The test answers are tracked and then analyzed so they can be compared with other members to create a compatible percentages. Members can then view these matches when they log on to OkCupid. One of the unique things at OkCupid is, these tests are created not only by staff but by users as well and cover all sorts of topics, whether serious or goofy. Members of OkCupid to date have answered more than 500 million 3 part questions, which equals over 1.5 billion pieces of data. From this data, personality trends are calculated based on 60 axes in which OkCupid tracks (religion is one such axis). Each member information is compiled and compared to each axis, which is also compared with others of your gender, age and sexual gender preference.

As other dating sites like Chemistry and Perfectmatch promote the fact that they have famous psychologists working for them to help create matching systems, OkCupid has stated that they don't need psychologists because their own members create their match algorithms. The UberAlgorithm takes care of figuring out each person's personality and the user tells OkCupid what type of person they want to date.

OkCupid has created a very interesting matching system that does work for a number of people. The problem is taking tests is not every persons cup of tea. This is why OkCupid tends to attract singles in their low to mid twenties. OKCupid hopes that as these singles age and mature, they will continue to use their site, increasing their over 30 age demographic. By being a free dating site, OkCupid doesn't have the funds for a research team of psychologists to help design a matching system. While users who know specifically what they want shouldn't have a problem with their matches on OkCupid, it's the members who are not sure that may suffer poor matches. Based on the members own personality, a match system needs to know that what the member is asking for in a partner is something that is compatible with his or her personality and requirements, not because that is who they think would make a good match. It is the job of the automated match system to know what makes a relationship last.

For the full interview, read Gelf Magazine. For more details on this dating site, read our OkCupid.com review.

One of eHarmony's senior research scientist is psychologist Gian Gonzaga. He holds a doctorate in personality / social psychology from UC Berkeley. KansasCity.com has a short interview with him where he describes briefly what the core qualities partners need to share to have a successful relationship.

The big ones — some of the most powerful ones — are personality traits. Things like how agreeable of a person you are, how open you are to experience. Are you extroverted? So are you looking for a lot of interactions in the social world? Or are you introverted?

Dr. Gonzaga also talks about why it matters that couples share these types of traits.

Because if you are similar to someone, it’s a lot easier to understand what it is they’re thinking. ... They like to believe that what they think is true, and one of the ways that we do that is to look to other people who have the same interests and beliefs and values. So when we see that in a partner, we feel validated in our sense of self, which makes us feel better and makes us like that person.

He further explains that opposites may attract but, these type of relationships really don't last. If you are really different from your partner, negotiating the way you see things from how your partner does over and over again, as each new conflict situation arises, is extremely difficult to do. Over the long run these type of relationships just fizzle out.

Dr. Gonzaga mentions Compatible Partners as well. This is eHarmony's new dating site for gay and lesbian relationships. He was asked a question about if gay relationships share the same characteristics as a heterosexual relationship:

We think so. The existing literature on same-sex couples indicates that a lot of the same theoretical basis of sharing the same deep values is going to predict better relationships over the long haul. So right now we’re moving on the assumption that the same kinds of models are going to apply well, and then over time we’ll work on that model to tailor it as best as possible.

This is the first time that I know of were eHarmony has said they are going to spend some research money to see if gay relationships actually do differ from heterosexual relationships.

For more information on this popular personality matchmaking site, read our eHarmony review.

We have discussed DNA dating before in previous stories which we mainly took a look at the dating site Scientific Match and how the actually process of DNA matching works. The Times Online has a detailed article called DNA dating: has science unlocked the secret of a perfect match? which expands on this and looks at other DNA based dating site like GenePartner.

GenePartner was started by Dr. Tamara Brown, a Croatian geneticist based in Zurich in the fall of 2008. For 5 years (2003-2007) she did research at the Swiss Institute for Behavioural Genetics were:

She believes she has found the attraction formula — based on patterns in the HLA genes — and turned it into a computer program, an algorithm that she is keeping to herself.

They currently charge $99 USD for a genetic match and at this moment have about 500 clients who come from the United States, Germany and the United Kingdom. When asked about her research and studies into DNA and matchmaking, Brown says she has no plans to publish it for scientific review until she has built up her clientele. She doesn't want to give her competitors any advantages. GenePartner also recently created a Facebook Application (just search for GenePartner on Facebook) to help boost member numbers. The App allows users to find out how biologically compatible you are and it also allows you to get tested directly through your facebook profile. Currently the GenePartner Facebook application has only 52 monthly active users.

One interesting topic which was brought up dealt with the protection of your DNA information when processed by a private genetics company. Since DNA testing is unregulated, some people fear this information could be sold to other companies. You wouldn't want your Insurance company to have your DNA results to find out what genetic problems you have. If they did, you could be discriminated against and denied health insurance. To fight this alarming issue, countries like the United States and Germany have passed laws which make it illegal for employers and health insurers to demand DNA tests or even be allowed to use a customer's genetic information against them. New York and California have gone even a step further and have ruled that genetic tests can only be ordered by a medical doctor, since it is a medical test.

Read the 4 page article to find out more about GenePartner, how it works and the science behind DNA matchmaking at Times Online UK.

We have talked before about the dating site called Scientific Match which uses DNA and the body's natural fragrance to match compatible singles (see Story). The Discovery Channel has an article which examines the dating site and the science behind it called Major Histocompatibility Complex or MHC for short. The idea is that opposite immune systems attract, thereby making it easier for any offspring of the relationship to fight off disease. To back up the science in their match system, ScientificMatch.com has more than:

40 peer-reviewed and published studies documenting the positive effect of different MHC's in couples.

The problems in which Scientific Match is having, is trying to gather enough members to be able to create proper matches. Plus these matches are not cheap and cost nearly $1000. Plus, Scientific Match still needs to screen potential matches for the normal profile attributes like location, age range and other preferences. That is why they are now considering licensing the technology to other dating sites.

For the full story, check out The Discovery Channel website.