The QR code has become ubiquitous as a way of sharing digital data on posters, signs and packaging. The tiny black and white dots are very vulnerable to being misread, and yet QR codes are very resilient. This activity explores just how resilient they are, and shows an error control method in action.

Facilitator preparation

• Read through the guide on how to deliver CS Unplugged at a distance content.
• Go through the slides and trial them with the video conference software that you are going to present with.
• If you aren’t familiar with the original unplugged activities, review the in-person version of the lessons (based on product codes and parity error correction).
• Make sure when you share your screen you also select to share the sound from your computer as this presentation contains a video.
• In your pre-session messaging to participants encourage participants to have a separate device (perhaps a phone or tablet) with a QR reader app enabled, or a camera that reads QR codes.

This session supports the learning in the following CS Unplugged at a distance sessions:

• Parity card magic (where students see how extra bits are added to some data, and an error can "magically" be corrected).
• Binary data representation (where students can explore how just two values (such as black and white) can represent numbers, text and more, using only a small set of cards).

Supporting Resources

• Computer Science Field Guide - QR Code Generator