CSFG
English Deutsch Beta Español Beta język polski (2.6.0)
Chapters Curriculum Guides Appendices

Coding - Error control
9.5. The whole story!

Coding - Error control

  • 9.1. What's the big picture?
  • 9.2. The parity magic trick
  • 9.3. Check digits on barcodes and other numbers
  • 9.4. QR codes
  • 9.5. The whole story!
  • 9.6. Further reading

The codes discussed in this chapter are all widely used, but the most widely used codes for data storage are more sophisticated because they need to deal with more complex errors than a single bit changing. For example, if a CD is scratched or a hard disk has a small fault, it's likely to affect many adjacent bits. These systems use codes based on more advanced mathematical concepts. The most widely used codes for storage and data transfer are the Reed-Solomon codes and Cyclic Redundancy Check (CRC). For human readable numbers such as barcodes, bank numbers, tax numbers, social security numbers and so on, checksums are very common, and the Luhn algorithm is one of the more widely used. Larger checksums are also used to check that downloaded files are correct. The parity method is a form of Hamming code.

Previous:
QR codes
Next:
Further reading

Looking for something for primary schools? Check out CS Unplugged.

The Computer Science Field Guide is an online interactive resource for high school students learning about computer science.

Useful Links

  • About
  • Chapters
  • Interactives
  • Curriculum Guides

Community

  • Twitter
  • YouTube
  • GitHub

Help

  • Search
  • Glossary
  • Feedback

Switch to teacher mode

English | Deutsch | Español | język polski (2.6.0)

The Computer Science Field Guide material is open source on GitHub, and this website's content is shared under a Creative Commons Attribution-ShareAlike 4.0 International license. The Computer Science Field Guide is a project by the Computer Science Education Research Group at the University of Canterbury, New Zealand. Icons provided generously by icons8.

3.12.6

This definition is not available in English, sorry!