Editing ACT-R (section)

===Theory vs. implementation, and Vanilla ACT-R===
The importance of distinguishing between the theory itself and its implementation is usually highlighted by ACT-R developers.

In fact, much of the implementation does not reflect the theory.  
For instance, the actual implementation makes use of additional 'modules' that exist only for purely computational reasons, and are not supposed to reflect anything in the brain (e.g., one computational module contains the pseudo-random number generator used to produce noisy parameters, while another holds naming routines for generating data structures accessible through variable names).

Also, the actual implementation is designed to enable researchers to modify the theory, e.g. by altering the standard parameters, or creating new modules, or partially modifying the behavior of the existing ones.

Finally, while Anderson's laboratory at [[Carnegie Mellon University|CMU]] maintains and releases the official ACT-R code, other alternative implementations of the theory have been made available. These alternative implementations include ''jACT-R'' <ref>Harrison, A. (2002). jACT-R: Java ACT-R. ''Proceedings of the 8th Annual ACT-R Workshop'' [http://act-r.psy.cmu.edu/workshops/workshop-2002/talks/AnthonyHarrison.pdf PDF] {{webarchive |url=https://web.archive.org/web/20080907005223/http://act-r.psy.cmu.edu/workshops/workshop-2002/talks/AnthonyHarrison.pdf |date=September 7, 2008 }}</ref> (written in [[Java (programming language)|Java]] by Anthony M. Harrison at the [[Naval Research Laboratory]]) and ''Python ACT-R'' (written in [[Python (programming language)|Python]] by Terrence C. Stewart and Robert L. West at [[Carleton University]], Canada).<ref>Stewart, T. C. and West, R. L. (2006) Deconstructing ACT-R. ''Proceedings of the seventh international conference on cognitive modeling'' [https://web.archive.org/web/20180127084017/https://pdfs.semanticscholar.org/1357/6cb9ffe422e11e6042ba76f3dcefd081baf8.pdf PDF]</ref>

Similarly, ACT-RN (now discontinued) was a full-fledged neural implementation of the 1993 version of the theory.<ref name="actrn">Lebiere, C., & Anderson, J. R. (1993). A connectionist Implementation of the ACT-R production system. In ''Proceedings of the Fifteenth Annual Conference of the Cognitive Science Society'' (pp. 635–640). Mahwah, NJ: Lawrence Erlbaum Associates</ref>  
All of these versions were fully functional, and models have been written and run with all of them.

Because of these implementational degrees of freedom, the ACT-R community usually refers to the "official", [[Lisp (programming language)|Lisp]]-based, version of the theory, when adopted in its original form and left unmodified, as "Vanilla ACT-R".