Make a quantitative bivariate map in ArcMap

Summary

Instructions provided describe two methods of building two-way classed symbology in ArcMap for the purposes of making a bivariate map.

Procedure

• Use the ArcMap Quantity by Category layer symbology option. This option is designed to do Quantity by Category mapping, but can be used to create a Quantity by Quantity map.
  
  Use grouping in the primary Unique values symbology to create classes of values. In this way Unique values are used to mimic a quantitative representation. The secondary symbology (Size or Color) is already quantitative and classed.
  
  

  Note:
  To group values into the same class, select several symbols or values, right-click, and click Group. 
  

  To group unique values:
  
  A. Use your mouse to select values.
  B. Right-click and select Group Values from the popup menu.
  

  
  
  

  Note:
  If Graduated Colors is selected as the secondary option, the Quantity by Category method builds colors by combining the color in the primary and secondary symbology. The method works in Hue, Saturation, and Value space. Hue comes from the primary symbol, and Saturation and Value come from the secondary symbol.

  
  
• Use the ArcObjects developer sample by way of the Related Information section below. This sample builds true Quantity by Quantity symbology automatically. It allows the user to pick from three different color combination methods.