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From: W.ElDeredy@ucl.ac.uk (Wael El-Deredy)
Subject: [Q]: Missing Output Values !?
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Date: Wed, 26 Apr 1995 13:33:43 GMT
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In an muti input/ multi output mapping,  the outputs are (measured) analog 
responses to the input stimuli. It should be straightforward to train a 
network to predict the responses given a new input.

The problem: Some of the training set input vectors don't have their 
corresponding output vector fully defined. i.e. some outputs are missing (due 
to a failed or unreliable measurement of that particular response).  

What would be the best strategy to propagate the error if one (or more) of the 
target values is (are) missing ?

One way is to eliminate the vectors with incomplete outputs from the training 
set. However, this may reduce the training set size significantly. 

Any suggestion ?



Wael El-Deredy                               W.ElDeredy@ucl.ac.uk
Dept. of Neurological Surgery                Tel +44 (0)171 837 3611 x 4169
Institute of Neurology - Queen Square        Fax +44 (0)171 278 5069
London WC1N 3BG, UK


