Answer:
A farmer cultivating blackberries has observed a decrease in his crop yield compared to prior years. He suspects that wildlife might be consuming the berries before he can harvest them. The farmer considers that the culprits could be either birds, which land on the bushes to eat, or rodents, climbing up to munch on the berries. He plans to first investigate the possibility of bird interference and seeks advice from a local expert on effective bird deterrents. He manages eight fields, each with ten rows of berry bushes. In one specific field (illustrated below from an overhead view), he covers half of the rows with nets designed to keep birds from landing, while leaving the other half exposed. He monitors the berry yield from each row over the span of eight weeks.
What are the independent (treatment) and dependent (response) variables in the farmer's investigation?
a) The independent variable is the number of rows while the dependent variable is the quantity of harvested berries.
b) The independent variable is the presence or absence of nets while the dependent variable is the number of rows.
c) The independent variable is the quantity of harvested berries whereas the dependent variable is the nets' presence or absence.
d) The independent variable is the presence or absence of nets with the dependent variable being the quantity of berries harvested.
Answer:
The independent variable is the presence/absence of nets, while the dependent variable is the number of berries collected. (d)
Step-by-step explanation:
Independent variable: This variable is the one that is fully manipulated by the experimenter in a scientific study. It can take any value as decided by the experimenter. In this case, the farmer determines which rows will have nets affixed or not, making the presence or absence of nets entirely under his control.
Dependent variable: This variable's values depend on the outcomes of the independent variable and is the focus of the study by the experimenter. In this scenario, the number of harvested berries is the dependent variable because it relies on whether birds can access the berries protected by nets, which, in turn, depends on the nets being present or not.