What is the purpose of including control samples in an experiment?

The inclusion of control samples in an experiment primarily serves to establish a baseline for comparison. This means that control samples represent a standard or reference point against which the experimental results can be measured. By having a control group that is not subjected to the experimental treatment or that receives a known treatment, researchers can clearly observe the effects of the experimental variables. This comparison helps to determine whether any changes observed in the experimental group are due to the treatment itself or are simply a result of other factors.

For example, in a study examining the effect of a new drug on disease progression, the control group might receive a placebo. By comparing the outcomes of the experimental group receiving the new drug with the control group receiving the placebo, researchers can assess the actual effectiveness of the drug. This ensures that the conclusions drawn from the experiment are based on unbiased comparisons, enhancing the reliability and validity of the results.

In contrast, other options discuss manipulation of outcomes or reproducibility, which, while important aspects of experimental design, do not directly address the primary purpose of control samples as establishing a reference point. Additionally, simply increasing sample size does not inherently provide a baseline for comparison, as it does not account for the specific effects of treatments versus controls. Overall, establishing a baseline via