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In experimental design, a control group plays an essential role. It serves as the baseline for comparison and does not receive the experimental treatment. This helps researchers understand the effect of the experimental variable. By comparing results from the control and experimental groups, researchers can determine the influence of changes introduced. Without a control group, it's difficult to attribute changes in the variables specifically to the experiment because there is nothing to benchmark against. In the given exercise, neither of the groups serves as a control group. Both groups follow specific instructions regarding answering questions truthfully or with a mix of truths and lies. A control group would typically just answer questions without any instruction to deceive or focus entirely on honesty.

A blind experiment is one where the participants are kept in the dark about certain elements of the study to prevent bias in responses. This precaution ensures that their natural responses aren't influenced by the knowledge of the experiment's details. For instance, subjects might alter their behavior if they know what the researchers are investigating. However, in the given exercise, participants are aware of how they should respond to the questions. Each group knows whether they are supposed to answer truthfully throughout or mix truths and lies. This implies that the study is not blind, as the participants’ awareness could unconsciously bias their responses.

A double-blind experiment takes the blinding a step further by preventing both the participants and the experimenters from knowing which group the participants belong to. This design minimizes any unconscious bias from the experimenters and participants alike. When neither party knows the group assignments, the integrity of the results is better maintained. In the exercise situation provided, the person administering the test does not know which subjects belong to which group. However, the subjects themselves do know their condition—whether they should be truthful or deceitful. Therefore, this setup only meets the criteria for a single-blind experiment, as only the administrator lacks full knowledge of the group specifics. To achieve a double-blind experiment, neither the subjects nor the administrator should be privy to the grouping information.