Hi Uday, Thanks for the reply. I will check that out, although I’m really keen to find an implementation of Poli and McPhee’s method — it seems like the most principled method in the literature, in that it is theoretically-derived. Thanks David On 13 Apr 2016, at 16:00, Uday kamath <[log in to unmask]<mailto:[log in to unmask]>> wrote: Look at the https://github.com/eclab/ecj/blob/master/ecj/ec/gp/breed/SizeFairCrossoverPipeline.java Found it fairly doing well in controlling the bloat. Cheers Uday On Wed, Apr 13, 2016 at 10:37 AM, White, David <[log in to unmask]<mailto:[log in to unmask]>> wrote: Hi Everyone, In 2008, Poli and McPhee published “Parsimony Pressure Made Easy: Solving the Problem of Bloat in GP.” In the paper, they outline a fairly straightforward way of controlling mean program size in a GP population. Has anyone implemented this in ECJ, please? I’d like to use it and don’t want to repeat the effort if it’s already been done. Thanks! David