Accordion

There are too many items to fit into a limited space without overwhelming the user.

Add / Subscribe

A person wants to subscribe to the content of another person and read it in an environment of their own choosing.

Carousel

User needs to browse among a set of like objects represented pictorially.

The Competitive Spectrum

The designer needs to match the reputation system to the community's degree of competitiveness.

Favorites

A user wants to mark an item (person, place or thing) as a preferred object.

Invite

The user sends an invitation to a friend or group of friends to have them join in a site experience.

Page Grids

For consistent use of common page elements, page width, division of space, ad usage and code base.

Reflector

A user needs to know what public identity she is participating under when creating content.

Saving

A user wants to save an item for later viewing, sharing, or discussion.

Sign-in Continuity

A user with an account but who is not currently signed in wants to participate by contributing something.

Talk Like a Person

People reading impersonal text on a screen will remain disengaged.

Terms of Service

Users often don't notice TOS checkboxes and get harassed by error messages.

User Card

A user needs to get more information about another participant in an online community without interrupting his or her current task.

You're Invited

The user receives an invitation from a friend or connection to join a site.

Your vs. My

Labeling stuff with Your reinforces the conversational dialogue. It is how another human being might address you when talking about your stuff.