Assigning Polarity to Connectors

Assigning polarity to connectors in your model lets you visually indicate the cause-and-effect relationship between model variables. Assigning polarity can also make it easier to tell a story about the feedback loops in your model.

A positive polarity (+) means that when the cause increases, the effect increases; the relationship between the variables goes in the same direction.
A negative polarity (-) means that when the cause increases, the effect decreases; the relationship between variables goes in the opposite direction.

For example, in the following model, when population increases, its effect is to also increase the effect of crowding (note the "+" polarity sign end of the connector). This is a positive polarity. Conversely, as carrying capacity increases, the result is to decrease the effect of crowding, a negative ("-") polarity.

Choose the polarity you want to assign (positive or negative), based on the interaction between the two variables.

To Assign Polarity to Connectors

Right-click the connector's handle, choose Polarity from the menu that appears, and then choose +, -, or None.