Section 6.2: Analysis

Possibly the most interesting part of this section is the latter half which deals with Homomorphisms.

Theorem 6.12: First Isomorphism Theorem

Let $f:R\rightarrow S$ be a surjective isomorphism of rings with kernel K. Then the quotient ring R/K is isomorphic to S.

If I understand this correctly then when comparing this to data transfer f represents the transfer of data from R to S where K is the amount of lost data. Looking at the kernel in Example 4 ($K={\mbox{all multiples of 6}$) we can say that $\frac{1}{6}$ of the data is lost during the transfer.