What Are The Three Factors That Influence Spatial Interaction Across Space?

What Are The Three Factors That Influence Spatial Interaction Across Space? Complementarity, intervening opportunity, and transferability are the three bases for spatial interactions. What are the three basic aspects for spatial interaction as described in Edward Ullman’s model? Ullman (1956) identified three conditions for spatial interaction: complementarity, transferability, and intervening opportunity. What are the principles