Final answer:
The missing component is that the researcher did not assign a treatment to each group of sod, which is critical for establishing cause-and-effect relationships within experiments. Random assignment of subjects to treatment groups minimizes bias and the influence of lurking variables.The correct option is:B) the researcher did not randomly pick the 30 pieces of sod.True.
Step-by-step explanation:
The missing component from the researcher's process is C) the researcher did not assign a treatment to each group of sod. This is a crucial step in experimental design to ensure that there is a controlled way to measure the effects of the treatment on the experimental units. When a treatment is not assigned, the validity of the experiment remains compromised because the researcher cannot attribute differences in outcomes to the treatment, thus undermining the ability to test cause-and-effect hypotheses.
Proper experimental design requires that all subjects experience both treatments, or that there are multiple groups where each receives a different treatment, with the order or selection of treatments being randomized.
Furthermore, to maintain the integrity of the experiment and avoid the influence of lurking variables, subjects or experimental units must be assigned randomly to different treatment groups. This also ties back to why choosing a random sample is effective: it ensures that every participant has the same chance of being part of the study and reduces bias.The correct option is:B) the researcher did not randomly pick the 30 pieces of sod. True.