Map Guide
The Map tool allows you to explore content geographically, visualize spatial distribution, and filter by location. This guide explains how to use the map and interpret location data.
Understanding the Map
The Map displays content locations using markers or heatmaps:
- Each marker represents content associated with that location
- Marker size or color may indicate the number of items at that location
- Clicking a marker shows details about the content
- You can zoom and pan to explore different regions
Geographic Layers
The Map supports different geographic layers:
View content distribution by country. Useful for broad regional analysis.
See content by city or urban area. More precise for local movements and events.
Some collections may define custom geographic regions based on movement boundaries or cultural areas.
Geocoding Process
Location data is processed through geocoding:
Location information comes from item metadata (city, country, coordinates, etc.)
Textual location names are converted to coordinates using geocoding services and standardized location databases.
Coordinates are validated and checked for accuracy. Ambiguous locations are flagged for review.
Location Confidence
Not all locations have the same level of precision:
Exact coordinates provided, or unambiguous city/country names. These locations are precisely mapped.
City or region name provided, but coordinates are approximate. Location is generally accurate but may not be exact.
Ambiguous location names, approximate regions, or uncertain data. These locations are mapped to the best available information but may be imprecise.
Location confidence is indicated in item metadata when available.
Geographic Ambiguity
Some location names are ambiguous and require resolution:
Many cities share names (e.g., "Springfield" exists in multiple countries). We resolve these using context clues from the content, author information, or other metadata.
Historical content may reference places by old names. We map these to current locations when possible, noting the historical context.
Vague references like "Northern Europe" or "West Coast" are mapped to approximate regions rather than specific coordinates.
Using the Map
- Click and drag to pan the map
- Use zoom controls or mouse wheel to zoom in/out
- Click markers to view content details
- Use location filters in search to focus on specific regions
- Combine map view with date or media type filters
- Search for specific cities or countries
- Identify geographic clusters of activity
- Compare content distribution across regions
- Explore connections between locations
Known Limitations
Some regions may be underrepresented due to limited source availability, language barriers, or collection focus.
Not all items have precise coordinates. Some are mapped to city centers or approximate regions.
Historical content may reference places that no longer exist or have changed names. We map these to current locations when possible.
Some content (especially recent online events) may not have physical locations and won't appear on the map.
Example Scenarios
If content mentions "Springfield," we use context (author location, related content, date) to determine which Springfield is intended. If ambiguous, we may map to the most likely location or flag for review.
If an item has coordinates but they're approximate (e.g., "near downtown"), we map to the provided coordinates but note the imprecision in metadata.
Best Practices
- Use the Map to identify geographic patterns, then investigate with search
- Combine Map with Timeline to see how geographic distribution changes over time
- Be aware of location confidence levels when interpreting results
- Consider coverage gaps and collection biases in geographic analysis
- Use specific location filters in search for precise geographic queries