E.H. Weber, a German psychologist, proposed the measure of JND (Just Noticeable Difference) within the year 1934. Weber gave the observation that the dimensions of the differential threshold are proportional to the intensity of the quality stimulus. This ratio is constant. The size of the differential threshold, a continuing ratio of the quality stimulus, is … Read more


You have so far come to know that area of psychophysics concerns the relationship between stimulus intensity and sensory magnitude. Fechner, extending Weber’s law believed that a general equation, with the logarithmic relationship, does exist that holds good for all senses. What Weber Says Weber’s law tells us that each just noticeable stimulus increment is … Read more


Gustav T. Fechner (1801–1887), professor of physics at the University of Leipzig, sought to measure the mind quantitatively. In approaching this task he studied stimuli and the sensations they aroused. His interest was in ascertaining how sensations changed with changing stimulation. While lying in bed on the morning of October 22, 1850, he conceived the … Read more

Eysenck’s Trait Theory

Hans J Eysenck is somewhat difficult to identify or classify as to whether he is a learning theorist or behaviourist. He supports a model of personality characterised by types and traits because he firmly believes that the most fundamental personalitycharacteristics are inherited. His equally strong belief that both heredity and environment determine behaviour supports his … Read more

Allport’s Trait Theory

Gordon Allport was one of the first modern trait theorists. Allport and Henry Odbert worked through two of the most comprehensive dictionaries of the English language available and extracted around 18,000 personality-describing words. From this list, they reduced the number of words to approximately 4,500 personality-describing adjectives which they considered to describe observable and relatively … Read more