QR Codes are essentially the picture form of a hyperlink. They can link to websites, PDFs, videos, audio files, and most other digital sources. They're super useful, and a great way to link students to other resources without the clutter of hyperlinks (or the risk of a typo and getting "lost" on the internet!). They can be read by most smartphones, tablets, and other devices, so as long as you have an internet connection, they should work just fine.
I use QR Codes as a way to point students to share resources with my students, to do station learning or scavenger hunts around the classroom, or even to share contact information with parents or other professionals. QR Codes are very easy to make and there are several free websites and tools teachers can use to create them.
To the right, I've included an infographic I created with several QR codes; this is like a WebQuest but not as in depth. I would walk through the infographic section by section with younger students when introducing a research essay, but would just hand it out as a helpful resource for older students to clarify different citations styles (especially those going to college soon who may need to learn to follow other style guides).
QR Codes can help teachers in several areas of Danielson's Framework for Teaching. In Domain 1 (Planning & Prep) it helps teachers design learning experiences that are appropriate to the lesson and the students. For Domain 3 (Instruction), QR Codes help teachers in formative assessment, especially if designing a scavenger hunt or Web-Quest style activity because the teacher can easily monitor student progress and proficiency. It also connects to Domain 4 (Professional Responsibilities) well if teachers use it to communicate with parents or colleagues to schedule meetings and keep track of those events. [1e, 3c, 3d, 4c, 4f]
This tech tool also integrates some of the ISTE Standards for students into the classroom as well. By using QR Codes to as a beginning of the year survey, teachers can help their students become more Empowered Learners (1a, 1c, 1d), and if the students are shown how to create and use their own codes, they will become Knowledge Constructors (3c) and Creative Communicators (6a, 6d).