Four short links: 9 September 2009

SMS Data Collection, Love of Math, Anti-File Sharing Rubbish, Open Manufacturing

  1. RapidSMSa free and open-source framework for dynamic data collection, logistics coordination and communication, leveraging basic short message service (SMS) mobile phone technology. UNICEF’s mobile data collection framework, as used in Malawi and other proving grounds. (via gov2expo)
  2. Groceries — read this and you will realize that Dan Meyer is the math teacher you wish you’d had. He has the geek nature, and his excitement must be great for his students. The express lane isn’t faster. The manager backed me up on this one. You attract more people holding fewer total items, but as the data shows above, when you add one person to the line, you’re adding 48 extra seconds to the line length (that’s “tender time” added to “other time”) without even considering the items in her cart. Meanwhile, an extra item only costs you an extra 2.8 seconds. Therefore, you’d rather add 17 more items to the line than one extra person! I can’t believe I’m dropping exclamation points in an essay on grocery shopping but that’s how this stuff makes me feel.
  3. How the UK Government Spun 136 People into 7 Million — a radio show looked into the government’s claim of 7 million illegal filesharers and discovered it came down to 136 people in a survey admitting they’d used it. (via br3nda)
  4. Idle Speculation on the shan zhai and Open Fabrication (Tom Igoe) — shan zhai have established a culture of sharing information about the things they make through open BOMs (bills of materials) and other design materials, crediting each other with improvements. The community apparently self-polices this policy, and ostracizes those that violate it. Open hardware, business, recovery, and more in this fascinating speculation.
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  • Furicle is partly right. Experienced shoppers know all about this kind of stuff. Meyer has identified only one of many relevant factors. (Note that he begins with “all else being equal”).

    You have to consider, at least: the number of shoppers in the line, the number of groceries in the line, the checker, the bagger (if present), the nature of the shoppers in line (e.g., someome likely to fumble with the payment process or someone likely to have their toddler press buttons on the machine or someone who’s there to get out quickly?), and the nature of the groceries in the line (e.g., how many price checks are likely to be needed). Watch out for lines where someone is sorting through their big wad of coupons, too.

    You also have to consider the level of competition for various lines. The decision process is real-time. For example, even if there is a clearly shorter line 3 aisles away, will it remain shorter long enough for you to get there?

    Finally there are wild-cards that are very hard to predict with any accuracy such as when a shift change on the register might cause a delay or when the checker might, say, run out of of quarters.

    The best strategy I’ve found is to pick a reasonable seeming line and then not worry too much about it.

    And never forget the wisdom of Apu (of the Simpsons). Marge: “Why pick that line? It’s so long!” Abu: “Yes, but look: it’s all pathetic single men. Only cash. No chit-chat.”


  • ObbieZ

    In my experience, I’ve seen rookies assigned to the express line. Express lines are often “no checks, no plastic, etc.”, so the more experienced checkers are on the non-express line to more ably handle these added duties.

    More importantly, I often wonder why more grocery stores don’t set up lines like banks or post offices, where there’s one line to wait for the “next available” clerk. Seems to be a fairer method of managing traffic than forcing customers to guess which would be the faster line.

  • obbiez: your “bank-line” idea doesn’t work because the stores need an efficient packing of carts into the smallest possible space. Basically. the store has to average a certain amount of revenue per sq. foot and margins are tight so it’s very hard to imagine giving up a bunch of potential shelf space just for a long “fair” queue of carts.


  • The headline on #3 is more misleading than what the government originally did. The 136 was 11.6% of the responses to a “survey of 1,176 net-connected households”. That’s a good sample size for a survey.

    There were problems, including having an interested party be involved in the research, but a more sensible comparison would be 3.9 million (mentioned at the end of the article) vs 7 million.