[ACT-R-users] matching score

[Sarah Schimke]

Hello,

I have the following problem with an act-r model:
the model works on the symbolic level and also when the
 subsymbolic computations are turned on by ":esc".
But when I'm adding noise by ":ans", there are a lot of
failures of retrieval because the different chunks take
matching scores that I don't understand.
In particular, the matching score turns to "nil" for chunks
the model is trying to retrieve directly (by a request like
for example "+retrieval> =goal"), so that a failure gets
retrieved instead of the chunk. This happens often, but not
all the time. 
Why does this happen?

Sarah Schimke
university of Freiburg