Mixing can be built into the dance choreography or can be structured to occur more randomly.
Some people may take advantage of mixers to assess dance skills of other persons without fear of being stuck with a poor match for an entire dance.
The descriptions of "mixing procedures" vary, however there are several common basic rules.
They separate, men and women each walking along opposite walls to the start end of the hall where they meet their next partners.
The randomness in partner matching arises from the different speed of travel and often different numbers of men and women.