Physiological Measures - Geer and Maisel
Whenever someone exposed to a stressor. Their stress reactions can be psychological or physiological.
Psychological = e.g. Fear or anxiety
Physiological = e.g. Increased heart rate; Galvanic Skin Response (GSR); Sweating.
Physiological measures of stress can overcome the subjectivity of a self-report by relying on hormones through blood/urine samples etc.
Stress can be measured by using any device to measure levels of arousal. GSR measures electrical resistance of skin in the nervous system.
Geer and Maisel (Info about study refer to G&M cause of stress card) used photographs to collect physiological/psychological data. GSR electrodes were placed between the palm and forearm of the lesser used participants arm. This data is then converted from a voltmeter to a printout. The data changes in accordance to skin and conductance, like heart or brain activity.
Conclusion: Stress can be measured using physiological measures and can provide evidence valuable data.