Thanks for the reply. I've implemented the statistics chain method, which works fine. Cheers David Sean Luke wrote: > Interesting question. prepareToEvaluate has a different purpose than > what you're looking for. What you want to do is have the prototype > Problem generate its test cases prior to being cloned each > generation. You could do this by overriding the > Evaluator.evaluatePopulation method to call some method on the Problem > and then calling super.evaluatePopulation. Alternatively you could > stick in a Statistics subclass into the Statistics chain which > overrides its preEvaluationStatistics method to call the method on the > Problem. > > Sean > > On Jun 24, 2008, at 10:42 AM, David R White wrote: > >> Hi, >> >> I would like to create a single set of test cases for all individuals >> in a generation, and still be able to use multithreaded evaluation. >> Is it possible to do this in an elegant manner? If I use >> "prepareToEvaluate" then it will be called for each Problem instance >> that is cloned, i.e. once for each thread, and as my test cases are >> probabilistically selected I will end up with a different set of >> tests cases for each thread, which I don't want! >> Any help appreciated, >> >> Thanks >> >> David >> >> -- >> >> David R White >> PhD Student >> Dept of Computer Science >> University of York, UK.