Comprehension of stress is of importance in order to minimize its detrimental effects on the body and mind and better computer user interface systems. Current scaling systems of stress are very rudimentary and are usually based on psychological questionnaires. In this thesis study through the use of electroencephalography (EEG) the effects of stress on brain function will be analyzed and the plausibility of a stress scale will be examined. Three experimental designs were created in order to analyze naturalistic stressors, non-stress and stimulus based stressors to give a comprehensive overview of variations in stress. The results showed that variations in stress do exist and that a scale can be devised by measuring internal and external stimuli in an individual’s environment. Results also showed that there are characteristics in brain functions associated with stress both in region and wavelength. The findings show that computer systems can use brain functions to characterize stressful states in order to better robotic systems which are user interaction based. Quantification of stress may be possible based upon the analysis of stimuli in order to improve mental health and the well being of individuals. An approach combining the analytical analysis of brain function and stimuli inputs would effectively generate a plausible stress scale.