It’s another Teachable Tuesday, and today we’re looking at QR codes. Sure they’re ugly and often misused, but these two-dimensional versions of the traditional barcode can be quiet impressive when used properly.

First, let’s take a look at how a QR code works. A standard QR code will have three large squares, one for each corner minus the bottom-right. These are ‘finder’ squares, which help your smart phone’s scanner determine when it is looking at a QR code. The smaller square in the remaining corner is the ‘alignment square’, and it tells your smart phone when it is looking at the QR code from the proper direction/distance. Most of the remaining space on the QR code is used to store data in binary code (see last week’s Teachable Tuesday for more on binary). Unlike traditional barcodes, which must be read mechanically by analyzing the thickness and spacing of vertical lines, QR codes are digitally read from both horizontal and vertical patterns, allowing for far greater data storage. A typical QR code is capable of storing up to 4000 text characters.

The big problem most people have with QR codes isn’t with how they work, but with how they’re used. If you scanned a QR code on an Amplify Media business card and it took you to http://www.amplifymedia.ca/, you could be forgiven for being annoyed at going through the necessary steps to scan a QR code when you could have simply typed our address into your web browser. However, if you scanned a QR code and suddenly all of Amplify’s contact information was entered properly into your phone’s Contacts, you might be a bit more pleased with the code’s function.

Fortunately for QR code designers and users, this is just scratching the surface of the code's utility. Check out the video below to see how Tesco South Korea is using QR codes to allow customers to shop for groceries as they commute on the subway, and to be greeted with promptly delivered orders as they return home.

Got a tech question you’d like us to explain? Ask it in the comments, and we’ll respond on a future Teachable Tuesday