Security Gate as Visual Minisystem

In discussing the four types of visual devices, author Gwendolyn Galsworth also notes that these devices may be combined into a "visual minisystem." She gives two good examples in her book on Visual Systems - a turnpike toll plaza, and a modern school bus. Both combine an assortment of visual indicators (signs), visual signals (grabs attention), and visual controls (limits behavior) to share information and allow a person to perform (or not perform) a desired task.

In libraries, the security gate entrance and exit is a good example of a "visual minisystem." The gate allows people to filter in and out of the library at a desired (controlled) area. It collects census information going in, and serves and important security role on the way out. If the security alarm is tripped, both an audible and visual signal is applied. This alerts both the patron and the staff that their immediate attention is required. In turn-style security gates, a bar physically counts patrons on the way in, and stops patrons on the way out if they trip the system. This adds a visual guarantee (allows correct response only) to the visual minisystem!