An improved analysis for an information system is described in which the input and output alphabets consist of (equiprobable) ordered lists of m items, with two distortion criteria: 1) the fraction of item-pairs found out of order and 2) the fraction of items found in wrong positions. For the former it is shown that, as

, the rate-distortion function

is equivalent to

with, for small

,

. For the latter,
![R_{2} (D) = m \\log m(1 - D) + m(l - D)[\\log (1 - D) - 1] + o(m)](/images/tex/5532.gif)
.