1.1.1 Non-text Content
+Sufficient
+Applies to all technologies that present a digital geographic map. A digital geographic map is a representation of two or more features in geographic space, using points, lines, or polygons, typically rendered visually. A map communicates generalized spatial information and relationships. This covers static map images (PNG, JPG, PDF), interactive web maps (Leaflet, Mapbox GL, MapLibre, OpenLayers, Esri ArcGIS, Google Maps, Bing Maps), and map components in native applications surfaced through the web. The framework also extends naturally to other two-dimensional spatial representations such as floor plans, circuit boards, and anatomical diagrams, though it was designed and validated against geographic maps.
+The objective of this technique is to provide a text alternative for a digital geographic map that serves the equivalent purpose by satisfying every applicable criterion of the Map Equivalent Purpose Framework (MEP Framework) against a visual (or non-text) baseline.
+Unlike visual maps and tactile maps, where centuries of cartographic practice have produced standard representation techniques, text maps have no standard representation technique. Different authors produce widely different text alternatives for the same visual map, and authors and auditors often disagree on whether any given text alternative actually serves the equivalent purpose of the visual map. The MEP Framework provides a common vocabulary and a set of measurable criteria for making that decision.
+The fundamental purpose of every two-dimensional digital map, regardless of any sub-purpose (historical, navigational, analytical, thematic), is to communicate generalized spatial information, spatial relationships, and any defined routes. The MEP Framework decomposes that purpose into four categories. The text alternative satisfies this technique when, for the visual baseline map, every applicable criterion in each category is met. A criterion that is not present on the visual baseline (for example, a static map has no temporal information, or a reference map has no defined routes) is marked N/A and excluded from the evaluation.
+Generalized means that "something" is being used to approximately represent the real world. The primitive map symbols are points, lines, and polygons. The Generalized category asks whether every point, line, and polygon for every object on the visual map is present on the text map. Every feature on the visual map needs to be present on the text map. There should be no shapes or features on the visual map that are not present on the text map, even if the feature lacks any label.
+If the visual map shows an unlabeled polygon for a body of water, the text map needs to contain a polygon for that body of water. If the visual map shows a thin gray line for an unnamed service road, the text map needs to contain that line. Omitting features the sighted user can see, including unlabeled features, fails the Generalized criterion.
+Spatial Information is about where features are, and what they are like (shape, size, orientation, location, and other properties). The Spatial Information category asks whether the shape, size, orientation, name, type, and any thematic, temporal, or sensory properties are present for each object on the text map, in enough detail for someone to redraw the feature. For each object on the map, the text alternative needs to contain, whenever the property is present on the visual (or non-text) map:
+If a property is not present on the visual map for a given object, mark it N/A for that object.
+Spatial Relationships are the connections between multiple objects: the location, distance, topological intersections and adjacencies, and direction between objects that are core to understanding the information in the representation. The Spatial Relationships category asks whether the reader can position any drawn feature in its correct relationship to every other feature, equal to what is present on the visual (or non-text) map. For each pair of objects on the map, the text alternative needs to contain, whenever the relationship is present on the visual baseline:
+If a relationship is not present on the visual map for a given pair of objects, mark it N/A for that pair.
+Routes are the defined paths on the map: how to get between two or more features on a map following a particular defined path, including the Spatial Information and Spatial Relationship elements for the route object, with the route information as prevalent in the text map as it is on the visual map. Typical defined routes include a turn-by-turn route, a designated trail, a bus line, or a defined evacuation path. If the visual baseline map has no defined routes, this entire category is N/A. If the visual baseline map shows defined routes that are not present on the text map, this category fails.
+For each defined route on the visual map, the text alternative needs to contain:
+If a property is not present on the visual map for a given route, mark it N/A for that route.
+The text alternative serves the equivalent purpose when every applicable criterion (excluding N/A) in each of the four categories above is satisfied for every object, every object pair, and every route on the visual baseline map. If any applicable criterion fails, the text alternative does not serve the equivalent purpose, and this technique is not satisfied.
+The following examples are actual text map representations evaluated against the MEP Framework in a published study (Biggs, Sloan, Oppegaard, Giudice, Coughlan, & Walker, 2026), each paired with the visual baseline provided in the study. The first two pass every applicable MEP Framework criterion and the third fails. Full per-criterion evaluation results for each example, including the verbatim text content of the Audio Description, are available from the MEP Framework repository.
+The text alternative is an Audiom interactive text map of Pacific Northwest COVID-19 data, an interactive spatial text map with keyboard-based navigation. The reader moves between state polygons with arrow keys at a user-specified distance, and this repetitive movement allows for the understanding of shape, size, orientation, distance, direction, and topological relationships. Thematic information is presented in the label for each object, as well as in a menu and a table. The visual color and pattern descriptions are provided in the alt text in the legend. Every state polygon on the visual baseline is present. Each state exposes shape, size, orientation, name, type, thematic information, and sensory information (color shading). Distance, direction, absolute coordinates, and topological adjacencies between every pair of states are programmatically queryable. Every applicable MEP Framework criterion passes against the visual baseline. Equivalent purpose is satisfied.
+The text alternative is a long-form structured Audio Description of the Pacific Northwest COVID-19 thematic map, authored in a word processor following audio description guidelines and indexed by headings and paragraphs. Every state polygon present on the visual baseline appears in the text, with shape, size, orientation, name, type, thematic information, and sensory information for each state, and with distance, direction, absolute coordinates, and topological adjacencies between every pair of states. Every applicable MEP Framework criterion passes against the visual baseline. The full verbatim text of the Audio Description is available from the MEP Framework repository linked above. Equivalent purpose is satisfied.
+The text alternative is the table representation of a fictional map of COVID-19 data, based on the same data shown on the visual map. The table has one row per state and one column per numeric or categorical property (case count, deaths, and so on). Generalized fails: the table contains no points, lines, or polygons, so no state polygon shape is present. Spatial Information fails on Shape, Size, Orientation, and Sensory information for every state. Spatial Relationships fail on Distance, Direction, Location (absolute and relative), and Topological relationships for every pair of states; the table preserves only state names and thematic values, not spatial structure. A follow-up empirical study (Biggs, Toth, Coughlan, & Walker, in press) corroborates this evaluation: tables significantly underperformed both visual maps and interactive text maps on geographic-based questions across both sighted and blind and low-vision participants. Equivalent purpose is not satisfied. Tables that lack geographic information cannot serve as a sufficient text alternative for the underlying map.
+For each digital geographic map on the page:
+