Polarity

In a causal loop diagram, or influence diagram, signs adjacent to an arrowhead indicates polarity. A plus (+) sign implies that a change in the variable at the tail of the arrow will cause a change in the variable at the head of the arrow in the same direction. Similarly, a minus (-) sign implies that a change in the variable at the tail of the arrow will cause a change in the variable at the head of the arrow in the opposite direction. (Richardson, 1985: 159). A similar notation applies to concept and cognitive mapping except that in these we are dealing with connected concepts rather than connected parameters. Also see concept and parameter.