Herman A. Witkin was an Americanpsychologist who specialized in the spheres of cognitive psychology and learning psychology. He was a pioneer of the theory ofcognitive styles and learning styles. He preferred to diagnose not by questionnaires but by other means, such as projective tests, task-solving tests etc. He was the author of the concept of field-dependency vs. field-independency. The majority of Witkin's research was done during his tenures at the SUNY Downstate Medical CenterCollege of Medicine in Brooklyn, NY and at Educational Testing Service in Princeton, New Jersey, where he worked until his death in 1979. A Review of General Psychology survey, published in 2002, ranked Witkin as the 96th most cited psychologist of the 20th century. Herman Witkin studied differences in perceptual style for almost 30 years. His first book was titled Personality Through Perception. The idea in this book was that personality can be revealed through differences in how people perceive their environment. Witkin was at first interested in the cues that people use in judging orientation in space. What makes one know that what one sees is a tilted object and that it is not you who are tilted? For one to find a conclusion, one examines other objects in the surroundings. In 1948, Witkin and Asch developed an apparatus called the Rod and Frame Test. When using the RFT, the participant sits in a darkened room where he or she receives instructions about watching a glowing rod surrounded by a glowing square frame. The researcher can manipulate both the rod, the frame and the participant's chair in different angles of tilts. The participant is then instructed to adjust the rod so that the rod is perfectly upright. For the participant to be able to do this, he/she has to ignore cues in the visual field. If the participant adjusts the rod so that it is leaning in the direction of the tilted frame, then that person is said to be dependent on the visual field. This person will be categorized as field-dependent. On the other side there will be people who are field-independent. These people will disregard the external cues, and use information from their bodies in adjusting the rod to appear upright. Field-independent people seem to rely on their own sensations instead of the perception of the field, to make a judgment. The Rod and Frame Test is a difficult and time-consuming method for revealing field-dependence and -independence. Witkin therefore developed the Embedded Figures Test. This test also measures field dependence without relying on the cumbersome Rod and Frame Test. An example of an EFT is a picture with many hidden figures which you are supposed to find. Field-independent people will quickly be able to find the hidden figures, while field-dependent people will have trouble locating the simple figures embedded within the more complex surroundings. Witkin found a strong correlation between the Performance on the EFT. Field independence-dependence has been linked to many traits. People who are field dependent have many more utterances per unit time in conversation with other field dependent people than do field independent people. Field dependent folks have better memories for faces. Field independent people have better memories for numbers. One paradigm experiment involved college students. In the experiment, the subject arrived late at a psychology experiment in which the other 'subjects' were asked to rate whether two lines were of equal length or unequal. The only seat for the subject was at the end of the semi-circle of other subjects, all of whom had been prompted how to respond to the prompt. Even when the lines were of clearly unequal length, the 'stooges' replied that the lines were of equal length. Subjects who were field-dependent also agreed that the lines were equal. Field independent subjects asserted the lines were unequal, even when the differences were very small. Field independence-dependence has been demonstrated in many cultures worldwide and appears to be bi-modal, although with advancing age it appears to drift toward the middle of the distribution. After Witkin's death, little research was done on field independence-dependence. However, new research began to appear in the beginning of the 1990s. Among the contributors were Vrij, van der Steen & Koppelaar and Linda Bastone & Heather Wood.