It is, in fact, the answer to any question concerning subjective evaluation. The existence of confirmation bias and the many other biases humans are subject to is firmly established and sticking your fingers in your ear and saying "naaaaaaa" won't make it go away.
It's not that hard, grind up a pile of each weed labeled "1" and "2" then leave the room and have someone else who isn't around your buds all day come in and roll five joints from each pile and label the joints "A", "B", "C" etc... writing down which joint comes from which pile. Now nobody knows which one is which, a.k.a. double blind. If the taste might give it away then put the buds and finished joints in a bag with some orange peel so they both smell/taste like orange peel. Now you can smoke the joints over the course of the next few days/whatever and write down which you think is which. If you don't get them all right then odds are you can't tell the difference. If you get them all right, do it again and see if you can get 18/20 because sometimes you can get 10/10 just by chance.
Remember, audiophiles will swear up and down they can hear the difference between ordinary wire and super special audiophile wire that costs hundreds of dollars a foot. The truth is that they do in fact hear a difference but it isn't because of the wires but because their own brains are fooling them.
