What is a "hybrid" model?

[Jeff Shrager]

I need to clarify something regarding the paper I mentioned in my note
to Ron about hybrid models.  I made a joke at the end of my note which
seems to have gone over everyone's heads.  

The paper that I referred to:

 Siegler, R.  S., & Shrager, J., (1984).  Strategy choices in addition
   and subtraction: How do children know what to do? In C.  Sophian
   (Ed.), Origins of Cognitive Skills. Hillsdale, NJ: Lawrence Erlbaum
   Associates. 229-294. 

Is NOT a forthcoming TR; It's an *old* *published* paper.  Since it's
old I don't have it online and can't send it to you in postscript
format, nor put it into the archive.  However, since it's published in
a somewhat obscure place I'm happy to send it to you, but you need to
send me your hardcopy address!  (I'd really appreciate it, though, if
you'd try just once to find the book in your local library first,
since I have to both do the work of photocopying the papers and
mailing them out to you.)

Thanks very much.

Cheers,
  Jeff

(The joke was that I played on Ron's "forthcoming TR" and called our
 paper, above, a "forthcame-TR."  I'm sorry; I realize now that this
 was way too subtle for email correspondence.)