> Redundancy helps to recover partially damaged data. Redundancy 1:5 means that for every 5 consecutive data blocks, if one block is completely unreadable, PaperBack will be able to restore it. To reduce damages caused by coffee pots and other common dangers, blocks are distributed around the page. Higher redundancy decreases page capacity but improves reliability.

Please do study error correcting codes. Most of them can offer much better error correction with less overhead. Take a look at Wolfram's MathWorld article [1]. This topic is heavily covered in most information theory books.

[1] http://mathworld.wolfram.com/Error-CorrectingCode.html