The 14-letter word you are referring to is known as "conducting controlled experiments." In scientific research, conducting controlled experiments involves carefully manipulating variables and controlling other factors to reduce the influence of chance errors or extraneous variables that could affect the results. To conduct controlled experiments, scientists meticulously plan and establish controlled conditions, such as using control groups, randomization, blinding, or replicating the experiment to ensure accurate and valid results. By implementing these techniques, scientists can reduce the impact of chance errors and draw more reliable conclusions from their experiments.