1 Associations. 2  Associations between actors and use cases are indicated in use case diagrams by solid lines. 3  An association exists whenever an actor is involved with an interaction described by a use case.
Benefits of Volunteering. Volunteering supports the Exploratorium and promotes hands-on science, artistic expression, and educational innovation. Volunteers contribute to the community while gaining additional experience and new skills. They get to know each other at gatherings and special events and by sharing their ideas and experiences via an e-mail list.
In addition to the mental health benefits of volunteering, there is also a benefit to your physical health. Volunteering allows you to be constantly going about, keeps you busy, and highly active. Research has shown that volunteers have a lower mortality rate compared to those who choose not to.