Group purpose statements can form your group’s anchor and identity. It’s important to make this explicit, and also revisit it periodically as the community evolves. These don’t need to be rigorous and formatted explicitly in multiple-parts. Choose something simple that works for you.
About Us statements answer really basic questions like who the group is for and what its goal is. What group is the group?
Mission statements are practical, and tangibly help manage the group: What the group does and how it does it?
Don't start out too broad, start simply and build on the natural growth of the group.
Vision statements are more aspirational and can inspire people to get involved: What better future is the group working towards?
Questions to ask:
Is it clear, short, and understandable?
Does it avoid jargon? (Or use jargon intentionally :)
Are we filling a need?
If there are many groups discussing the same broad topics, you might want to consider a more niche focus for your group.
UK Dynamo User Group: A Group for Dynamo users across the UK to share knowledge.
Toronto Dynamo User Group: We are a community of visual programming enthusiasts striving to stimulate the exchange of innovative workflows and promote computational design… By facilitating a free and open platform for community engagement and technical discussion, organizing local community events to share and explore technological trends and innovative workflows, and seeking industry research opportunities, we hope to provide our peers with a valued and engaging space for professional growth.
RevitDC: To provide a forum for Revit users to share their ideas, methods, and practices in order to further the Building Information Modeling (BIM) benefits for the local design community in the DC area.
About Us: The Autodesk Group Network is a global network of user groups, developer groups, and online groups.
Vision: We envision a world where people connect in community to share knowledge and collaborate across firms and industries to improve the use of design technology and make a better world.
Mission: To create a global network of user groups and underpin this community with the tools and resources you need to: Manage user groups, Grow your communities, Connect and collaborate with other leaders, Reach personal and professional goals, Adopt new and better ways of working.
How to Create Collaborative Community Mission & Vision Statements (Vanilla Forums Blog)
Developing Vision & Mission Statements (Community Toolbox)