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False Positives, Few Matches Plague 'No-Fly' List

lindner writes "According to a recent article in the San Francisco Chronicle, the United States No-Fly List uses a soundex algorithm to match names. Designed 'to quickly summon passenger names or to catch deal-hunting passengers making duplicate bookings.' The system has only managed to rack up a slew of false-positives, including everyone matching soundex ("J. Adams") at one point in time. The problem has gotten so bad that there is now a "Fly List" for chronically misidentified passengers."

13 of 325 comments (clear)

  1. Re:Soundex??? by BWJones · · Score: 4, Informative

    That algorithm is so fundamentally broken as to be practically useless for anything but as an aid in simple searches. Why anyone would use soundex in a mission critical application designed to positively identify individuals is beyond me. What, was the 'No Fly' database written by 1st year comp sci major or something? Sheesh.

    Hey, wanna make a good living in these uncertain economic times? Come up with a better alternative and propose it to DARPA. There is actually some very cool research going on that is funded by DARPA in terms of biometrics and database centric comp sci.

    --
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  2. Re:Deal-Hunting is illegal? by Anonymous Coward · · Score: 3, Informative

    I think this has to do with the process of:

    (1) Register for flight with Airline X.
    (2) While registered for flight, search for better deal on similar flight with Airline Y.
    (3) Cancel flight with Airline X.

    Or I could be way off.

  3. Ten Problems with Soundex by notestein · · Score: 4, Informative

    Here's a good run down on soundex and ten problems with it.

  4. Uhh... metaphone? by Pyromage · · Score: 3, Informative

    The metaphone algorithm addresses many of the shortcomings of soundex... why are they not using it?

  5. Re:Deal hunting? by heli0 · · Score: 4, Informative

    what's wrong with passengers hunting for the best deal?

    Story: to catch deal-hunting passengers making duplicate bookings.

    This means that people were using different travel agencies to reserve lots of seats on the same flight, and then simply going with the agency who quoted the lowest price. This means that the seats end up being empty, and the rest of us end up paying for them. Sorry, but even the "rich elite" can no longer make duplicate reservations. Almost all airlines now use software to automatically cancel duplicate bookings.

    --
    Whenever the offence inspires less horror than the punishment, the rigour of penal law is obliged to give way...
  6. Reinventing the wheel by CodeMaster · · Score: 5, Informative

    This is unbelievable. Why reinvent the wheel, while there are at least 3 countries that have implemented similar restrictions and tracking systems succesfully for more than 10 years now (England, Israel, and Germany - that I know of).

    This sounds like the work of some consultants with no idea of what they are faced with and fresh out of collage where they have analyzed a couple of algorithms... sorry - I have had way too much of these running around the office lately

    If for once someone would just poke his head out and instead of trying to find a solution to an age old problem, look and see how others are handling it, we (taxpayers) would all be much more content (and safe...).

    Just my 2c.

  7. Why not use ID#? by jaclu · · Score: 5, Informative

    I guess all US people would screem for such a "threat to your privacy" ;)

    But at least in here in sweden basically anytime you book a flight you give your ID number (similar to a social security #)
    Two benefits:
    1. Name is just a courtesy, so doesnt really matter for security if somebody get my name wrong.
    2. On checkin, it must be _you_ not somebody with a similar name

    Of course IDs can be stolen or forged, but that is a problem regardles of how you ID your self.

  8. credit checks - wtf? by ananke · · Score: 3, Informative

    quote from the article: Scheduled for deployment in Spring 2004, CAPPS II will require airline ticket buyers to give more identifying information -- full name, birth date, home phone number and address. This information will be run against private credit-rating and government watch list databases to "verify you are who you say you are," Rosenker said

    What in the hell? I was under the impression that having a credit check actually hurts your credit history [as in, you shouldn't have too many credit checks in .] Now they're going to be checking that every time I fly?

    I always hated flying, now I'm starting to hate air lines...

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    --- d'oh
    1. Re:credit checks - wtf? by juuri · · Score: 4, Informative

      Not every check shows up on your reports, it is possible to make an overall query that doesn't get mentioned. FICOs scores are done this way.

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      --- I do not moderate.
  9. Re:Deal-Hunting is illegal? by PeteJones · · Score: 5, Informative

    I think the deal hunting they are refering to is the practice of buying 2 return tickets and then using the first set to get to your destination and the second to get back. This way you can get the cheap tickets that span weekend stays but instead travel on a, say, Tuesday and come home on Wednesday of the same week.

    Even though you bought two complete return fares, it's still cheaper most of the time that buying one return ticket during a business week. They are trying to fleese the business traveller to subsidize the vacation traveller. I think you probably get both sets of airmiles from buying 2 sets as well

  10. John Gilmore is suing for freedom of travel by morcheeba · · Score: 4, Informative

    John gilmore is suing for the right to travel anonymously(sp).

    From the website:
    He does so "because he believes persons have a right to travel by air without the government requiring that they relinquish their anonymity. No security threat is as important as the threat to American society caused by erosion of the right to travel, the right to be free from unreasonable searches, and the right to exercise First Amendment rights anonymously."

    Check out the FAQ's, which are well written and explain the other reasons - including being subject to secret laws - he is opposing this.

  11. Re:Soundex??? by PurpleFloyd · · Score: 3, Informative
    Soundex may or may not be crap, but half the calculation work (which is really easy) can be done when the name is written to the DB. Obershelp, on the other hand, requires a search for the largest common pattern, for which no work can be done in advance. Soundex is a matter of converting the name input into a Soundex code (first letter, 3 numbers) then searching the database for that code.

    Obershelp/Ratcliffe works well for finding the best match in small sets, but on a large DB, it breaks down completely unless you are willing to dedicate significant time to the search. While better alternatives to Soundex definetely exist, Obershelp/Radcliffe is not one that should be used in large databases.

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    That's it. I'm no longer part of Team Sanity.
  12. Re:Deal-Hunting is illegal? by aaarrrgggh · · Score: 3, Informative

    Oddly, I noticed it the other day on a "terms of use" disclaimer for United. It went something like "you aren't allowed to play with our systems to get a better fare."

    The two tricks are "hidden cities" and "double-booking." For a hidden city, you book a flight through where you really want to go, get off the plane, but have a remaining segment. Since you had to make a stop, that ticket is cheaper.

    The airlines really have a flawed pricing scheme. Maybe it made sense 15 years ago, but they really need to re-consider based on ...say what their cost is?