21.   Their method is simply to do controlled experiments.

22.   Their lives have unfolded almost like a controlled experiment.

23.   To overcome that problem, he devised novel controlled experiments to deal with the ecosystems of entire lakes.

24.   Unlike the Connecticut and Iowa evaluations, they were not designed as controlled experiments to separate the impact of welfare policy from the strong economy and other factors.

25.   Researchers caution this cache of doomsday genes has been unlocked only in controlled experiments.

26.   Results of the first carefully controlled experiment of aspirin in colon cancer will be made public at a cancer conference in April.

27.   There, he met professor Richard Alpert, who later changed his name to Baba Ram Dass, and began a series of controlled experiments with psychedelic drugs.