Basic Map Elements

Please consider these suggestions when creating maps

  1. Data in maps:
    1. The map frame(s) should take up a majority of the area; avoid excess white space. And the data you wish to show should fill each map frame (right-click and choose “activate” in order to change zoom level in the layout.).
    2. Inclusion of unnecessary data should be avoided; simpler is better.
  2. Map Titles:
    1. Should not be sentences, but should be simple and to the point.  For maps, a title should contain the subject of the map and the location
    2. Should not be the focal point of your map.
    3. Should almost always be black or dark text.
    4. Should be placed in a location on the map so as to not obstruct any other portion of the map.
  3. Scale bars:
    1. Scale bars are not appropriate for maps displayed in geographic coordinate systems, because scale changes across the map and when measured horizontally or vertically.
    2. You must have one for each map (except in cases portraying large areas where the scale changes across the map)
    3. Don’t have a scale bar that extends all the way across a page. Scale bars should not be the focal point of the map, they are for reference only. Make them small and place them on or below the map
    4. Scale bars should use appropriate measurement systems. Example: km for a county, meters for a campus. Use metric units please.
    5. Use intervals that make sense.  Units of 2,5,10, 20 are common. For example, do not accept the generated intervals like 23.4, or even 23.  Note that the ESRI default scale bar properties allows the interval values to change when the scale bar is lengthened or shortened.  You will always want to change this default so that the interval is fixed to avoid awkward interval values. Some examples from previous classes

      Can you really easily divide 0.9 miles into four parts (top left), or 16 (top right)? (And miles? Really? What scientist uses miles?) You control the size and number of divisions on a scale bar. Make it easy on your map reader. The 2 4 8 version is much easier to use (although I often use “km” instead of spelling it out)
  4. Map Borders are known as “neat lines.”:
    1. Maps need borders when they completely fill the area presented, and they should usually be black. This is the default.
    2. Neat lines should not detract from the focus of the map, i.e. overly thick or dark.
    3. However, when the map only fills part of the map frame (like a state?), you will likely want to remove the “frame” or neat line.
  5. North Arrows:
    1. I think they should be unobtrusive and simple (opinion; not “truth”)
    2. They are unnecessary and misleading on maps of large areas at small scales, i.e. where lines of longitude would show noticeable curvature.
    3. The default size of the ESRI default north arrows are universally too large – scale them down on your maps.  Likewise, the original intent of map north arrows was not decorative; they were the practical means of precisely orienting a map!  Some of us still use them that way…
  6. Legends:
    1. Legends should be unobtrusive
    2. Legends should only show features that are not labeled on the map or aren’t obvious from universally recognized symbols.
    3. Legends should only include the layer name (remove the “heading” when not needed), and the layer name should be edited in the table of contents to simple say what the layer portrays, not its original file name “lex_quad_DEM” should simply say “Elevation (m)”

      ESRI’s defaults really stink. For the left one, take off the heading called “Value’ and ax the “high” and “low” (sorry, both are ESRI defaults but detract from utility of the map). For the one on the right. Do you need “Legend” for one thing? For the right one, use “elevation (m)” instead of “demutm13s”which is a filename, and again, get rid of the “value” heading.
    4. Do NOT accept the ArcGIS default of 9 or 12 significant digits

      (do you really think we know elevation to the micron?). Be realistic.
  7. Map Text:
    1. Text should NEVER cross other text or other features of the SAME color.
    2. Labels for natural features such as streams, lakes etc. should be in italics.
    3. Text should be legible!  Save or print your final product at the reference scale of the map so that all symbols and text are properly scaled.
  8. Information:
    1. Your name, fairly small, should be on the map.
    2. The drive location of your work should appear on all map layouts. (use “Path”)
    3. Please include the “Projection” and “Datum” of any map on the layout, but not necessarily the rest of the spatial data (you’ll have to to hack the dynamic text box).
  9. White Space:
    1. Do not waste space. Try to find the balance between too much white space, and cluttered data.

This list was adapted from a course at the University of Texas at Austin. There is a free course at the ArcGIS Training site on map composition, if you’d like learn more.