An experiment that fails would be “I was trying to measure the speed of neutrinos, but I measured lab errors instead.”, or “I tried to titrate a solution, but used an excess of phenolphthalein accidentally.”
An experiment that fails would be “I was trying to measure the speed of neutrinos, but I measured lab errors instead.”, or “I tried to titrate a solution, but used an excess of phenolphthalein accidentally.”