Square dance square dance, very rarely are two modern Western dances ever alike. Like traditional square dancing, recovering from occasional mistakes is often part of the fun. Dancers are encouraged to dance only those programs at which they are reasonably proficient, the default level of achievement being the Mainstream program. All programs are set by Callerlab, the callers' international association, which also governs the training of callers. Irish and Scottish dances are normally done to traditional tunes. English dances may be done to traditional tunes, though, especially at ceilidhs, there is experimentation with many different musical styles. The two types of American
Activity diagram Activity diagram Activity diagrams are graphical representations of workflows of stepwise activities and actions with support for choice, iteration and concurrency. In the Unified Modeling Language, activity diagrams are intended to model both computational and organizational processes (i.e., workflows), as well as the data flows intersecting with the related activities. Although activity diagrams primarily show the overall flow of control, they can also include elements showing the flow of data between activities through one or more data stores. Activity diagrams are constructed from a limited number of shapes, connected with arrows. The most important shape types: Arrows run from the