As we use social tools on the web, design patterns are emerging. Social design must be organic, not static, emotional, not data-driven. A social experience builds on relationships, not transactions.

In 2008, Yahoo!'s Christian Crumlish introduced the idea of social design patterns to BayCHI. He returns in 2010 to share what he learned over two years. With his Yahoo! colleague Erin Malone, Christian created a wiki to gather social design patterns and published a snapshot of the wiki in book form.

Among the many principles of social design, Christian presents five:

• Pave the Cowpaths: Watch what people do, then support and adapt to that behavior.
• Talk Like a Person: Use a conversational voice. Be self-deprecating when an error occurs. Ask questions.
• Be Open: Embrace open standards. Support two-way exchange of data with other applications.
• Learn from Games: Give your application fun elements, like collecting and customization.
• Respect the Ethical Dimension: Understand the expectations people have in social situations and abide by them.

Christian then describes five practices:

• Give people a way to be identified and to characterize themselves.
• Create social objects that give people context for interaction.
• Give people something to do, and understand the continuum of participation, from lurkers to creators to leaders.
• Enable a bridge to real life.
• Let the community elevate people and the content they value.

Finally, he discusses five anti-patterns, commonly-used design choices that appear to solve a problem but that can backfire and pollute of the commons. Examples:

• The Cargo Cult: Copying successful designs without understanding why they are successful.
• Breaking Email: Sending an email alert, but rejecting or silently discarding the reply.
• The Password Anti-Pattern: Asking people for their password to another service encourages poor on-line hygiene.
• The Ex-Boyfriend Bug: Connecting people who share a social circle but who have reasons to avoid each other.
• The Potemkin Village: Building groups with no members. Instead, let people gather naturally.

Christian stresses that social design is an ecosystem in which designers must balance many trade-offs. Not every design pattern applies to every application, but good designers can use patterns to strike a balance that works.