You have to be using a random number seed. It's part of ECJ's parameters. I would check to see if it is set to a specific number. You can see what the parameter values you're using are by running with -p print-params=true Sean On Jan 26, 2016, at 11:31 PM, bijoy patwal <[log in to unmask]> wrote: > hi, > thanks for the reply. > I am not using random number seed.All the inputs are initialized. > > On Sat, Jan 23, 2016 at 4:01 AM, Sean Luke <[log in to unmask]> wrote: > On Jan 22, 2016, at 1:32 AM, bijoy patwal <[log in to unmask]> wrote: > > > I am always getting the same fitness for every evolution though . > > Are you using the same random number seed? > Try > seed.0 = time > > Sean >