Parameter learning problem

[John Anderson]

Well, thank you, Niels, for articulating the problem so well.  

More generally, your first solution raises the question about whether
there should be a q at all.  Rather, failures of the production should
probably reflect in an estimate of the b parameter as you suggest.  This
would get rid of the one parameter and avoid the problem that our
equation P = qr is in fact not usually correct.

As for your second solution, it has some appeal and has been a favorite
of Christian Lebiere for some time.  But as you say, it is radical. 
Maybe a topic for discussion at the next workshop.