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?

1) replicating each treatment, including the control.
2) assigning treatments to subjects or plots at random.
3) never performing the same experiment twice, but trying instead to improve each experiment.
4) Both a and b
5) None of the above

Answer 1

To mitigate the effects of uncontrolled variables, ecologists replicate treatments and randomly assign treatments, so the correct answer is option 4) Both a and b.

Step-by-step explanation:

Ecologists strive to design experiments that can accurately identify cause-and-effect relationships between variables. To reduce the influence of variables not under the control of the experimenter, they focus on experimental design and elimination of lurking variables. This is done by: replicating each treatment, including the control (to minimize the impact of random events and increase the reliability of data) and assigning treatments to subjects or plots at random (to ensure that these lurking variables are evenly distributed among the groups, which makes the only difference between groups the treatment imposed by the researcher). Therefore, the correct answer to the question is option 4) Both a and b.