Special Criteria for Evaluating Resources

When looking into purchasing geographical resources for a library, several things must be looked at to ensure that the best collection is purchased.  When evaluating these options the criteria may be applicable to other reference books, however atlases and maps have unique criteria in evaluation.  The criteria include scale and projection, color and symbols, publisher/authority, indexing and currency. 

Scale and projection is the most common criteria used in maps.  Scale represents the ratio of the distance on a map to the actual distance on earth.  Many of us have seen the scale indicated below a map.  See the example below.

^[1]

Any good map or atlas will include a scale so that readers can understand the map compared to the real world.  Projection on the other hand refers to the flattened image of a map compared to the globe.  The value of projections are still being discussed as maps tend to be distorted and errors occur when projections are made.  When purchasing these resources, librarians must be sure to include sources that have these aspects.

Colors and Symbols are extremely important tools when being used on maps and in atlases.  Color is used for a number of reasons like defining boundaries between states/provinces, countries, altitude, physical objects, bodies of water, population and many other boundaries.  Symbols are used to show many different things like the number of cattle in a particular town or crops in South America.  Symbols are normally accompanied by a key so that users can easily differentiate between the different symbols.  In well formatted maps, clutter is kept to a minimum so that users do not confuse symbols, colors and other marks on the map.

  
Librarians should be aware that there are superior publishers in the map and atlas fields.  While there are few sources that tend to publish inferior products, there are companies out there that are known as reliable and trusted.  Some well-known firms in the U.S. are Rand McNally, the National Geographic Society, and Universal map.    Keep in mind that there are also newer online publishers that publish maps of equal  quality including Omni Resources (http://www.omnimap.com) and East View (http://eastview.com).

Indexing and place names are an important feature to look at when selecting geographical resources.  Good maps and atlases should contain an index to make it easy to locate specific places on the map or in the atlas.  Indexing can use a grid format or provide exact coordinates of objects.  While the cost may be higher for maps and atlases that have quality indexing, the benefits surely outweigh the costs for patrons.

As we discussed previously, the world changes at an extremely rapid pace.  Keeping geographical collections current is the second most important aspect when selection this resources.  “A world atlas that is five years old portrays enough obsolete information that it should be used only for historical purposes.”^[2]  Libraries must remain current on their collections and materials to ensure that their geographical reference section maintains its purpose.

All of these methods of evaluation have something in common and that is that they keep the patron in mind.  They all seek to ensure that the patron can use the resources effectively.  Cost is a factor when it comes to quality resources and while some of these features cost more, the benefits will be evident.

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^[1] Math Dictionary, http://www.webquest.hawaii.edu/kahihi/mathdictionary/S/scalemap.php

^[2] Reference and Information Services – An Introduction, ed. Richard E. Bopp and Linda C. Smith (ABC-CLIO, LLC, 2011), 562.