How the human visual system determines the lightness of a surface, that is, its whiteness, blackness, or grayness, remains--like vision in general--a mystery. In fact, we have not even been able to create a machine that can determine, through an artificial vision system, whether an object is white, black, or gray. Although the photoreceptors in the eye are driven by light, the light reflected by a surface does not reveal its shade of gray. Depending upon the level of illumination, a surface of any shade of gray can reflect any amount of light.
In Seeing Black and White Alan Gilchrist ties together over 30 years of his own research on lightness, and presents the first comprehensive, historical review of empirical work on lightness, covering the past 150 years of research on images ranging from the simple to the complex. He also describes and analyzes the many theories of lightness--including his own--showing what each can and cannot explain. Gilchrist highlights the forgotten-yet-exciting work done in the first third of the twentieth century, describing several crucial experiments and examining the brilliant but nearly unknown work of the Hungarian gestalt theorist, Lajos Kardos.
Gilchrists review also includes a survey of the pattern of lightness errors made by humans, many of which result in delightful illusions. He argues that because these errors are not random, but systematic, they are the signature of our visual software, and so provide a powerful tool that can reveal how lightness is computed. Based on this argument and the concepts of anchoring, grouping, and frames of reference, Gilchrist presents a new theoretical framework that explains an unprecedented array oflightness errors. As both the first comprehensive overview of research on lightness and the first unified presentation of Gilchrists new theoretical framework Seeing Black and White will be an invaluable resource for vision scientists, cognitive psychologists, and cognitive neuroscientists.

The ISKO UK Biennial Conference, 4th - 5th July, 2011, London honoured the life and achievements of Brian C. Vickery. His influence on the development of the information profession is celebrated in this book, with contributions from over 50 authors to address research and developments in knowledge organization, ranging from the theoretical basis of information retrieval to the practical application of ontologies in driving news and sport presentation on the BBC website. ISKO UK is a not-for-profit scientific/professional association with the objective of promoting research and communication in the domain of knowledge organization, within the broad field of information science and related disciplines.

A practical guide to the construction of thesauri for use in information retrieval. In recent years, new applications for thesauri have been emerging, for example, in front-end systems, cross-database searching, hypertext systems, expert systems and in natural-language processing. In-house thesauri are still needed for internal special collections. The fourth edition of this work has been fully revised and the bibliography much extended, in particular, to include web addresses.