Which design principle refers to the patterned repetition of elements at intervals?

The design principle that refers to the patterned repetition of elements at intervals is rhythm. Rhythm in design is akin to rhythm in music; it creates a visual tempo and flow through the repetition of certain elements such as shapes, colors, or textures. This repetition can be consistent or varied, and it contributes to the overall composition by guiding the viewer's eye and enhancing the sense of movement within the design.

Rhythm can be seen in various architectural styles and design layouts where elements, such as columns, windows, or decorative features, appear at regular intervals, creating a cohesive and harmonious visual experience. This principle is essential in establishing a sense of unity and continuity, making it easier for the audience to navigate through the space and appreciate the design as a whole.

In contrast, hierarchy pertains to the arrangement of elements in a way that signifies importance, often using size, color, or placement to direct attention. Contrast refers to the juxtaposition of differing elements to highlight differences, while proportion deals with the relationship in size and scale between different parts of a design. While all these principles are crucial in creating effective designs, rhythm specifically focuses on the repetition and arrangement of elements, making it the correct answer in this context.