In the modern era, cars are all tested in controlled conditions with all of the variables that can affect performance well within the control of the engineer. (topspeed.com)
This experimental setup was used by the team to measure the electrical output of a sample of solar cell material, under controlled conditions of varying temperature and illumination. (sciencedaily.com)
Though, it may seem that the treatment is likely to be better, one can not know until it is tested under controlled conditions with objective ways of measuring data and responses. (vetmed.tamu.edu)