[comp.ai.neural-nets] testing generalization i NN

steensj@daimi.aau.dk (Steen Sj|gaard) (04/04/91)

Hi,

I am working on a project which deals with different network architectures and 
generalization. 
What I'm most interested in is to find out if there are any general ways to
determine the connectivity/arrangement of the "necessary" number of hidden 
units, when the main subject of interest is the networks' generalization 
ability. However, I desperately need a "well-sized" generalization problem
to train and test the different networks on. (By "well-sized" I mean a problem
which definitely is more complex (and realistic) than xor, parity and similar
toy-problems, but on the other hand also less complex/time-consuming  than 
NetTalk, e.g.)
I have talked to a lot of people about such a problem, but nobody seems to 
know of a "standard" or benchmark problem when it comes to analyzing 
generalization in neural networks. 

As I am sure that I am not the only one who finds this interesting, I would
therefore like to advertise for problems which actually have been successfully
applied to investigate the generalization ability of neural networks.

Any comments, ideas, suggestions, experiences????

                                              Thanks in advance
                  
                                              Steen Sjoegaard
                                              Comp. Sci. Dept.
                                              Aarhus University
                                              DK-8000, Denmark
                                              Email: steensj@daimi.aau.dk

egel@neural.dynas.se (Peter Egelberg) (04/11/91)

In article <1991Apr4.130549.12904@daimi.aau.dk> steensj@daimi.aau.dk (Steen Sj|gaard) writes:
>Hi,
>
	.
	.
	.
>I desperately need a "well-sized" generalization problem
>to train and test the different networks on. (By "well-sized" I mean a problem
>which definitely is more complex (and realistic) than xor, parity and similar
>toy-problems, but on the other hand also less complex/time-consuming  than 
>NetTalk, e.g.)
	.
	.
	.

Have you tried the two-spiral problem?

The objective of the problem is to train the network to predict in which
of the two spirals a given point lies in. The input points are given in
XY-coordinates. The spirals start out at the center and spiral outwards.
One spiral starts out pointing to the left and the other starts out
pointing to the right.

-- 
Peter Egelberg			E-mail:	egel@neural.dynas.se
Neural AB			Phone:	+46 46 11 00 90
Otto Lindbladsv. 5		Fax:	+46 46 13 60 85
223 65 LUND, SWEDEN