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.
Another way to measure the impact of volunteers is to take a look at statistics like hours served and the economic value of volunteer time. According to the Corporation for National and Community Service, 61.8 million individuals in the United States contributed 8 billion hours of volunteerism in 2008 alone. Volunteers help to keep our neighborhoods, streets, parks, rivers, green spaces, and water clean and safe for everyone. 2  Volunteers tutor, teach, mentor, coach, and support young people with everything from math homework to dealing with personal crises to football and soccer tourneys.