[Cover] [Contents] [Index] Previous page Next Section

Page 161
7.18 Definition Suppose 0161-001.gif and 0161-002.gif.
(a) The asymptotic uniform agreement between  a  and  b  on intervals of 0161-003.gif (written: auam( a ,  b )) is 0161-004.gif.
(b) The asymptotic uniform disagreement between  a  and  b  on intervals of 0161-005.gif (written: audm( a ,  b )) is 1 - auam ( a ,  b  ).
(c) An M Huexa,m-identifies f (written: 0161-006.gif) if and only if 0161-007.gif and 0161-008.gif.
(d) 0161-009.gif.
(e) 0161-010.gif.
If 0161-011.gif, then 0161-012.gif for all intervals I of length m or more. Note that there is no notion of an M Huexa-identifying a particular f. If 0161-013.gif, then for some m we have that for every interval I of length m or greater and for every 0161-014.gif, 0161-015.gif. The basic properties of the Huex criteria are easy to establish.
7.19 Proposition(
a) For all a, 0161-016.gif with a < b, 0161-017.gif.
(b) 0161-018.gif.
(c) 0161-019.gif.
(d) 0161-020.gif.
Proof: For parts (a), (b), (c), and (d), adapt the proofs of Proposition 7.7, Proposition 7.12, Corollary 7.11, and Proposition 7.10, respectively.
The most interesting property of the Huexa (for a < 1) criteria is that they fail to contain the Ex* criterion. That is,
7.20 Proposition 0161-021.gif.
Proving the proposition requires taking a closer look at the Exn criteria. This is accomplished in the propositions that follow, from which Proposition 7.20 is obtained as an immediate corollary.
A basic problem with the Exn criterion for large n is that it permits a scientist to converge to an explanation that is correct on all but n points, but these n points many include all the experiments for which one would like correct predictions. Proposition 7.21

 
[Cover] [Contents] [Index] Previous page Next Section