Best traing performance value?

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K M Ibrahim Khalilullah
K M Ibrahim Khalilullah 2016년 10월 16일
편집: Greg Heath 2016년 10월 17일
what is the best value for performance. I trained my data and the training performance graph look like this. How can I improve training performance?

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Greg Heath
Greg Heath 2016년 10월 17일
You are putting the emphasis on the wrong thing.
The performance estimate of the training subset is highly biased because you are using the same data for training and performance estimation. Because of this, the training subset performance is not used to rank the goodness of multiple designs.
Because designs usually start with random initial weights, typically, multiple designs are created and their performance is ranked using the nontraining validation subset. Since the validation subset is used to stop training when the ability of the net to obtain good performance on the nontraining validation set deteriorates, it's estimate is also biased.
However, the bias of the val subset estimate is relatively small. Therefore it is used to rank multiple designs.
Finally, to obtain an UNBIASED estimate of net performance the NONTRAINING TEST SUBSET is used in the net chosen via the validation subset.
Sometimes the m best designs are combined to form an ENSEMBLE in which the output is a (weighted or unweighted) average of the m nets.
In summary, the training subset and nontraining validation subset are used to obtain and rank multiple designs. However the unbiased estimate of the net performance is obtained by using the 1st ranked net on the nontraining test subset.
Hope this helps.
Thank you for formally accepting my answer
Greg
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K M Ibrahim Khalilullah
K M Ibrahim Khalilullah 2016년 10월 17일
Thank you for your answer. actually I have some misconception. would clear me about training performance value. what is the meaning or significance of training performance value/best training performance value?
Greg Heath
Greg Heath 2016년 10월 17일
편집: Greg Heath 2016년 10월 17일
The meaning? It is supposed to be a representative sample from the distribution that you use to design a net which is supposed to be valid for the whole distribution. This is called GENERALIZATION (e.g., interpolation and extrapolation).
The non training validation subset is part of the design process to make sure that the net generalizes; i.e., is useful for nontraining data.
The nontraining test subset is used to verify that the net will be useful for other nontraining data.
Another way to look at it is that the most important performance measure is the performance on nontraining test data. Training and validation data are just tools used to obtain that goal.
Hope this helps.
Greg

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