Gestalt psychology
Having specialized in figure–ground organization, Rubin spent the following two years as a research associate for Georg Elias Müller in Göttingen, Germany, examining the recognition of visual figures at different angles and sizes. His theories became influential within Gestalt psychology, yet Rubin is typically not included among the early influentials. Nor did he consider himself a Gestalt psychologist, being "sceptical of their attempts to construct wide-ranging theories". Nevertheless, his terminology was retained and featured in Kurt Koffka's "Principles of Gestalt Psychology".