What are the experimental units in his experiment? (Hint: Remember, experimental units are the entities to which the treatment is applied.)
The birds
The blackberry bushes
The rows of bushes
The fields
The correct answer and explanation is :
In this experiment, the experimental units are the blackberry bushes.
Explanation:
To understand why blackberry bushes are the experimental units, let’s first clarify the concept of “experimental units.” An experimental unit is the smallest division of the experimental material to which a treatment is applied. The purpose of identifying experimental units is to determine the level at which the treatment is applied in an experiment.
In this case:
- The birds: While birds might interact with the experiment, they are not the entities to which a specific treatment (like a certain type of growth medium, fertilizer, or experimental condition) is applied. The birds might be observed, but they are not the focus of the experimental manipulation.
- The blackberry bushes: These are the actual subjects to which the experimental treatments are applied. Whether it’s different types of fertilizers, pruning techniques, or exposure to different environmental conditions, the treatments are applied to these bushes. They are the experimental units because they are the entities being directly manipulated or observed in the context of the experiment.
- The rows of bushes: Rows are just an organizational structure. They are not individual entities to which treatments are applied. Each row might contain several bushes, but the rows themselves are not the experimental units. The individual blackberry bushes within the rows are the experimental units.
- The fields: Similar to the rows, the fields are the larger experimental setting. They might be the location where the rows of bushes are planted, but the treatment is not directly applied to the entire field; it is applied to the individual bushes within the field.
Thus, the blackberry bushes are the experimental units in this scenario because treatments are applied to these bushes, and the results are measured at the level of individual bushes, not at the level of the field, rows, or birds.