A Spatial Knowledge Acquisition Comparison Between Digital Visual Thematic Maps, Non-Visual Interactive Text Thematic Maps, and Tables

TL;DR

This study compares digital visual maps, interactive text maps, and tables in conveying spatial information, finding that maps outperform tables in geographic tasks and that accessible interactive maps can serve as effective map alternatives.

Contribution

It demonstrates that Web Content Accessibility Guidelines-compliant interactive text maps can effectively communicate spatial information, challenging current accessibility practices favoring tables.

Findings

Maps outperform tables on geographic questions across participant groups.

Participants preferred map-based representations over tables.

Perceived workload was highest for interactive text maps, lower for visual maps, and lowest for tables.

Abstract

Digital maps are used to communicate generalized spatial information and relationships, yet are commonly made "accessible" using tables that lack geographic information. This study examines whether these tables and interactive text maps (ITMs) may be comparable to visual maps. Twenty sighted and 20 blind and low-vision individuals (BLVIs) performed tasks designed to compare visual maps, ITMs, and tables. Participants answered numeric, geographic, and combined numeric geographic questions using each representation, and performance, preference, and NASA-TLX were measured. Across both participant groups, map representations (visual and ITMs) significantly outperformed tables on geographic-based questions, while performance differences were minimal for numeric questions. For sighted participants, performance on geographic questions did not significantly differ between visual maps and ITMs, indicating that a larger powered study may find an "equivalent purpose" across these two conditions. Participants preferred map-based representations over tables. Perceived workload was highest for the ITM, intermediate for the visual map, and lowest for the table. Consistent with the Map Equivalent Purpose Framework, these findings indicate that Web Content Accessibility Guidelines-compliant ITMs can provide access to spatial information, unlike tables. These findings challenge prevailing accessibility practice that recommends tables lacking geographic information as map alternatives, and motivate reconsideration of accessibility legislation exempting digital thematic maps.