Dear Laurie, There are multiple parsimony pressure methods in ECJ, and different methods may have different ways of being used, as well as specific parameters to be set. We have prepared three conference papers on the parsimony pressure methods in ECJ. You can find info about them from http://cs.gmu.edu/~eclab/pubs-long.html (just look for parsimony on the web page). One is available online, the other two are not (yet), but we could send them to you if you cannot access them otherwise. There is also documentation about the methods and their parameters (except for DoubleTournamentSelection which for some unknown reason is less documented) in the online documentation of each class: http://cs.gmu.edu/~eclab/projects/ecj/docs/classdocs/index.html I would suggest that you read the papers (at least briefly) and the class documentation in order to get an idea about the methods and figure out which one you'd want to use. I could assist you set the parameters once you know which one you want to use. Regards, Liviu. On Jul 26, 2005, at 11:06 AM, Hirsch Laurence wrote: > Hello, > > Could you let me know the recommended way to introduce parsimony > pressure? > Is it possible with a parameter? Ideally I would only like to > introduce it > toward the end of a run i.e. after a set number of generations, > > Thanks > > > Laurie