Abstract: A device is provided for measuring a subject's reaction to stimuli, i.e., to measure a subject's indication of attitude, opinion, judgement, preference, evaluation, feeling, intention, etc. when presented with a question, problem, fact, situation or other stimuli the subjective response to which is sought to be measured, said device comprising a first means having a defined viewing area and a colored means having at least one colored area adapted to be viewed in said viewing area wherein the extent of colored area viewable is variable and adapted to indicate the degree of a subject's reaction to a specific stimulus.