Have you ever used a mulcher to chop up some yard waste, only to accidentally put in some dog shit, and then the whole thing stinks to high heaven?
In all seriousness, with meta-analyses it's still "garbage in, garbage out". It only takes one or a few egregiously bad studies to throw off your results if that study has a large sample size but something fundamentally wrong with its methodology or implementation.
In all seriousness, with meta-analyses it's still "garbage in, garbage out". It only takes one or a few egregiously bad studies to throw off your results if that study has a large sample size but something fundamentally wrong with its methodology or implementation.