- help to locate places
- usually deal with a time period, either current or historical
- some deal with thematic or subject info
Categories of locational questions
- current events
- military history
- place name changes
Map: a drawing of all or part of the earth or universe, usually produced on a flat surface and almost always at a greatly reduced scale.
• Physical maps: trace various features of the land, e.g. lakes, rivers, mountains.
• Route maps: show features such as roads, railroads, bridges, hiking trails.
• Political maps: show various political boundaries eg. towns, cities, counties, countries
Some maps include all three types of info.
Large flat maps provide the most detailed geographic info.
- finding details of a local area such as streets, public buildings, churches, schools
- look at growth or decline of an area
- look at topography, drainage systems, woodland cover, and other physical and cultural features
Atlas: a planned or systematic collection of geographical maps bound in book form or kept loose in a binder or slipcase. Can provide whole world in one volume at nominal cost.
- Geographical: show important geographical or political features of the world.
- Historical: show boundary changes, military campaigns, or early exploration.
- Thematic: emphasize a specific subject or region, include national, population and geographical atlases
- locate places, countries
- understand historical development of a country or region
- look at a specific subject or theme in more detail e.g. world population
Gazetteer: geographical dictionary, usually of place names or physical features. Compliment and supplement atlases. Can be part of an atlas like an index or be separate publications.
- Locational: provide info for precise location of feature either by atlas page and grid index or by latitude and longitude
- Descriptive: locational info plus description e.g. brief history, population, altitude, commodities, etc.
- Find where a specific city, mountain, river, or other physical feature is located
- Find additional info such as population or perhaps leading economic characteristics of an area.
Cartography: the art and science of map making.
Cartographer: a map maker.
Travel guides: provide info about a place or country written to meet the needs of a particular group e.g. students, or level, e.g. inexperienced, traveler. May be written to meet the needs of the armchair traveler.
The only relatively accurate graphical representation of the earth is a globe but the need for a globe in a reference situation is probably questionable.
Maps and atlases have unique evaluation criteria
Scale and projection
- Scale: ratio of distance on map to actual distance in real world
- Projection: method used to transfer a curved section of the earth to a flat, two dimensional surface.
Scale: most important element of a map as it defines the amount of info that can be shown, as well as the size of the geographical area.
- The smaller the right hand number, the larger the scale of the map 1:75,000 is a larger scale map than 1:600,000 which is a small scale map.
- The larger the scale, the smaller the area the map can cover, but the greater amount of detail that it can include about that area.
- Scales given in numbers called representative fractions (RF):
1:100,000 means one unit of distance on the map equals 100,000 of the same unit on the surface being portrayed, e.g. the earth
- Small-scale maps are used for maps of wide areas where not much detail is required. For example, a small-scale map of Europe (e.g. 1:12,000,000) would fit on a single page (typically 8 inches by 11 inches).
- A medium-scale map of San Francisco (e.g. 1:300,000) would fit on a single page.
- Large-scale means a more detailed map. They are used in large applications where detailed local maps are required. A large-scale map of a small town (e.g. 1:24,000) would fit on a single page.
All maps are imprecise because projection of the earth’s curved surface onto a flat surface results in some distortion. To minimize or control distortion cartographers have developed numerous scientific map projections each of which has its own special uses, e.g. on world maps:
- Mercator projection shows correct shape of land masses but distorts their size.
- Google’s Interrupted Homolosine projection allows fairly faithful representation of both the shape and size of large land masses but distorts and interrupts the ocean area. \
Goode's interrupted Homolosine
Colour and symbols
Colour used for: political boundaries, contour lines, water, roads, railways, buildings, highways, vegetation, etc.
Symbols: amount and type controlled by scale of map
Map should be legible and easy to interpret. It should not be too cluttered.
- national mapping authority
- Rand McNally, C.S. Hammond, National Geographic Society, John Bartholomew, Oxford University Press, Michelin
As a rule, atlases lacking a general index, or at least separate map indexes should be avoided.
- Does index include all places and features shown on maps?
- Approx. how many entries are included?
- Single alphabet at back or separate indexes for each map or series of maps?
- Does index effectively refer you to right map and right point on map?
- How are variant place-names treated, and is there adequate cross-referencing?
- Does index offer any info beyond place-names and map references e.g. pronunciations, population stats?
Copyright date and date when maps prepared can vary widely. May represent a new printing with only minor corrections vs. a new edition with major revisions.