Control condition is the condition that helps in reducing the changes that can occur in variables in an experiment apart from the variables undergoing the experiment.It is considered as the independent factor in experiment as it will not depend on other factors while getting altered and change.
According to the question, Martina's experimentation lacks the presence of control condition which will not produce actual results. She is measuring reaction time of her friends in experiment without stabilizing control condition that is not considering level or state of friends even after providing same amount of coffee.
