The Law of Similarity states that people spontaneously perceive visually or contextually similar elements as belonging together. In Gestalt psychology, it is considered one of the fundamental principles for how the brain forms meaningful patterns and groups from stimuli.

Origin

The origin of this principle lies with the Gestalt psychologists of the early 20th century, in particular Max Wertheimer, who published fundamental research on it in 1923; Kurt Koffka and Wolfgang Köhler also made important contributions.

  • Wertheimer, M. (1923). Investigations into the Theory of Gestalt. Psychologische Forschung, 4, 301–350.
  • Koffka, K. (1935). Principles of Gestalt Psychology. New York: Harcourt.

Application in UX and UI design

In UX and UI design, the law of similarity ensures that similarly designed elements, such as buttons in the same colour or icons with similar shapes, are recognised as coherent function groups. This makes it easier for users to find their way around the interface and to associate similar actions with each other.

The principle is often used to structure complex content: similar font sizes, colours or spacing allow users to automatically cluster content, which supports visual hierarchy and information processing. Conversely, deliberately varying the appearance of individual elements can emphasise that they differ from others in function or meaning.

Impact on the User Experience

strong

Further information