Question

Ecologists try to reduce the likelihood that variables not under the control of the experimenter will unduly influence the results of an experiment by
a. carefully setting up experiments so that the results are identical and do not need to be statistically analyzed to prove the result.
b. assigning treatments to subjects or plots methodically.
c. never performing the same experiment twice, but trying instead to improve each experiment.
d. replicating each treatment, including the control.

Answer 1

They could influence the result by (d.) replicating each treatment, including the control.
In researching something unknown, we never know what factors that might influence a certain occurrence. One way around this is to keep changing all the treatment and control on research subjects in order to find out which factors that gave out consistent results