Methodical testing of tactile cartographic signs in isolation and in context

To date, the ways of testing tactile signs lack systematization. Hence, the aim of our research was to methodically evaluate the legibility of the proposed set of tactile signs. Our solution is based on the sign theory, in which signs have relations with reality, other signs, and users. We employed a two-step procedure by first assessing signs in isolation to verify the ease of decoding and differentiation of signs within the same geometry type, and then evaluating their correct interpretation in context – on a map with signs in different geometries. We validated our approach using signs designed for historic garden maps that formed our case study. We tested these signs across three matrices (for point, line and area signs). Most of the signs were correctly recognized by the study participants in the first attempt. Any illegible signs were redesigned and reevaluated in context using seven pseudomaps. At this stage, minor issues related to single signs arouse, primarily due to inappropriate pseudomap design rules rather than sign geometries themselves. Based on participants’ feedback, we refined the signs again, and finally obtained a standardized set of 52 legible signs, intended for 3D-printed tactile maps using the DLP technique. Our analysis confirms that the proposed signs are legible, regardless of the user’s skills and characteristics.