Museum research After receiving his PhD, Melton stayed at Yale as an instructor for three years. During this time, he worked on a project with Robinson at the
Philadelphia Museum of Art &
Buffalo Museum of Science which was funded by the
Carnegie Corporation and the
American Association of Museums. He published two important
monographs:
Problems of Installation in Museums of Art (1935 ) and
Experimental Studies of the Education of Children in a Museum of Science (1936). Melton examined the influence of variables such as the spacing of an art piece in a display on subsequent interest in the piece by museum visitors, by quantifying the amount of time spent looking at a specific piece of art and the total number of pieces observed.
University of Missouri In 1935, Melton obtained a position as the chairman of the Department of Psychology at the
University of Missouri on interpolated learning and with W. J. von Lackum (1941) on the two-factor theory of retroactive interference. Melton and Irwin had subjects learn a word list of associated words, then recall the words after varying numbers of trials on a second word list. They subtracted the number of overt intrusions (newly learned words from list two) from the total amount of retroactive interference (the amount of interference of memory for list one words as a function of the number of trials of list two). They found a phenomenon, which they called Factor X, that was large and systematically increased with the amount of interpolated learning of list two. They found that, at low levels of list one learning, the interference was largely due to overt intrusions, but with increased learning of list one, interference appeared be due to factor X. Over time, the number of intrusion errors decreased. They postulated that this was similar to the unlearning of an association suggested by
Clark L. Hull during
extinction. They suggested that errors in memory, forgetting, are a result of commission and omissions errors due to new learning. Factor X was responsible for the weakening or unlearning of first-list association during the learning of an interpolated list. With these papers, Melton extended prior work to show that
forgetting was due to both response competition and unlearning, which was dubbed the two-factor theory of
retroactive interference. Notably, the use of subtraction methods to reveal underlying processes would become a prominent method in studies of short-term memory and cognition after World War II. He helped develop a battery of psychomotor tests, assessing perceptual-motor coordination and related factors necessary for flying, for pilot selection in the
air force. The success of these tests was important to the prestige of experimental psychology in the military. Melton would later publish a monograph on these test batteries. Melton's leadership helped create and solidify an important role for psychology within the military, especially the training of psychologists who became leaders in experimental psychology after the war. Melton served as the Technical Director of the Air Force Personnel and Training Research Center at
Lackland Air Force Base in Texas and rose to the rank of
brigadier general during his time in the military.
University of Michigan Melton returned to academia in 1957 joining the Department of Psychology at the
University of Michigan. He and
Paul Fitts established the Human Performance Center which became one of the leading research and training centers for experimental psychologists. At Michigan, Melton continued his work on verbal learning and memory. In fact, Melton became a leading authority on memory across the world. His paper "Implications of Short-Term Memory for a General Theory of Memory" (1963) was a landmark. Melton argued for the continuity of
short-term and
long-term memory, which is consistent with modern theories of
memory, rather than the presiding theoretical framework at the time that they were structurally distinct. Melton reported that if a subject was given a free-recall list with words occurring twice, the probability of recall of repeated words was directly defined by the lag, the number of items that fall between the identical words, the Melton lag effect.
Service In 1951, Melton was appointed editor of the
Journal of Experimental Psychology, which he held for 12 years. He became a member of the
American Psychological Association's (APA) Board of Directors from 1952 to 1954 & 1962–1965, and chairman of the Board of Scientific Affairs from 1957–1958, member of the Policy and Planning Board from 1962 to 1965. Melton was on the APA Publications Board from 1957–1960 and the Communications Committee from 1970-1974. He was a founding member of the
Psychonomic Society and served on its governing board from 1968 to 1973. He served as president of the Midwestern Psychological Association, the APA Division of Experimental Psychology and Division of Military Psychology. == Later life ==