Types of Maps

Maps can represent data distribution for one or more variables in various ways:

Isoline Map: Connects places with the same particular values using lines.
- Example: Figure 1-23 shows an isoline map indicating corn production, where darker colors represent regions more important for corn production.
Dot Distribution Map: Depicts data as points to show clustering or spread over an area.
- Each dot represents a predetermined number of observations.
- Example: Figure 1-24 illustrates a dot distribution map for corn production, where more dots indicate higher corn production. Each dot represents 100,000 bushels of corn.
Choropleth Map: Uses shading or patterns proportional to the variable's measurement in recognizable areas.
- Darker colors typically represent the highest data range.
- Example: Figure 1-25 shows a choropleth map where darker states indicate higher corn production.
Graduated Symbol Map: Displays symbols that change in size according to the variable's value.
- Higher values are represented by larger symbols.
- Example: Figure 1-26 presents a graduated symbol map for corn production, where larger circles indicate higher corn production.
Cartogram: A map where the size of a country or U.S. state is proportional to the value of a particular variable (e.g., corn production) rather than actual land area.
- Distorts the scale to represent the variable.
- Example: Figure 1-27 shows a cartogram where the size of states is proportional to corn production. Iowa appears larger than Texas because it produces more corn.

Corn Production Examples:

Isoline Map (Figure 1-23): Depicts regions of corn production with varying color intensities.
Dot Distribution Map (Figure 1-24): Uses dots to represent the amount of corn production, where each dot equals 100,000 bushels.
Choropleth Map (Figure 1-25): Shades states based on corn production levels; darker shades indicate higher production.
Graduated Symbol Map (Figure 1-26): Uses circles of varying sizes to indicate corn production levels.
Cartogram (Figure 1-27): Resizes states based on corn production, showing states like Iowa larger than Texas due to higher production levels.

Corn Production Scale: