Guide to QR Codes
Introduction to QR Codes
What are QR Codes?
Quick Response (QR) codes are two-dimensional barcodes (matrix codes) that allow their contents to be decoded at high speed. They were created by Japanese corporation Denso-Wave in 1994 and have been primarily used for tracking purposes, but have only recently filtered into mainstream use with the creation of applications that allow them to be read by mobile phone cameras.
How Can You Read Them?
Users can scan in codes (maybe in a magazine or on a poster) using a mobile phone with a camera or QR reader and QR Code reader software. The decoding software then interprets the code. QR software can be downloaded from the Web: a list of applications suitable for a variety of handsets is available from Tigtags . Users are then provided with a relevant URL, chunk of text, transferred to a phone number or sent an SMS. This act of linking from physical world objects is known as a hardlink or physical world hyperlinks.
Figure 1: QR Code for the UKOLN Cultural Heritage Web site
Creating QR Codes
To create a QR Code you will need to access a QR Code generator; then, enter the required information. The output is an image file that you can save to your computer. There are a number of freely available QR code generators, including Kaywa  and i-nigma . An effective QR code should generally be a maximum of 40 - 80 characters (more characters cause the image to degrade), black and white, and a minimum of 2cm wide.
Currently not all mobile devices have the capacity to include a QR code reader, and there are also issues regarding cost and speed of access to networks. QR codes have a limited number of characters, and use is currently limited to one action per code.
Potential of QR Codes
QR Codes have great potential within learning and teaching, for example, by linking to online resources and allowing user interaction. They are also a great tool for linking information to locations and objects, for example, in museums or through the creation of treasure trails. The QR Codes at Bath blog  offers many ideas for uses. They can also be used in conjunction with other services (such as a library catalogue) or as a marketing aid by putting onto posters, t-shirts, etc. They are very cheap to produce. In December 2008, Pepsi became the first high-profile consumer brand to use QR codes.
QR Codes in the Museum
A blog post on the PowerHouse Museum blog  identified a number of opportunities and possible problems in making use of QR codes with extended objects. The blog post suggested that QR codes are probably best seen just as mobile-readable URLs. However, initial experiments with QR codes identified a number of difficulties; including, the fact that not all QR codes are the same, inconsistent size of QR codes, and making a mobile-friendly site.
- QR codes at Bath,
- QR codes in the museum - problems and opportunities with extended object, PowerHouse Museum blog, 5 March 2009,
QR Codes - What are they? (slideshow)
QR Codes page on Library Success: A Best Practices Wiki
7 Things You Should Know about QR Codes
from Educause Learning Initiative
QR Codes and academic libraries: Reaching mobile users, by Robin Ashford (from College & Research Libraries News)
QR Codes Connect Students to Books (school libraries)
by Lauren Barack
Hot QR Codes in the Classroom & Library from The Daring Librarian (blog)
All About QR Codes and the Library's Snap & Go Project
from Contra Costa County Library
QR Codes and Libraries
compiled by Katrina L. Miday Library Consultant, State Library of Ohio
Some quick tips:
Decode QR Codes Without a Camera
from Free Technology for Teachers blog
This work is licensed under a  Creative Commons Attribution 3.0 United States License