• Large chart paper (one per group)
• Markers in multiple colors
• Central question written on each paper
• Timer

Write a thought-provoking central question on each chart paper. Arrange room for groups of 4-6 around tables with chart paper. Assign marker colors to track individual contributions.

1. Explain Silent Discussion (also called Chalk Talk): Entire activity is in complete silence. All communication is written.
2. Central question today: 'Should scientists be allowed to edit human genes to prevent disease?'
3. Rules: No talking. Write responses to the central question AND to each other's comments. Use lines to connect related ideas. You may write questions, agreements, challenges, or new ideas.
4. Each person gets a different colored marker to track contributions.
5. Begin. Walk around silently, writing on any chart paper. Respond to others' ideas.
6. Teacher participates too - modeling thoughtful written responses.
7. After 10-15 minutes, signal a 2-minute warning.
8. End the silence. Gallery walk: Groups rotate to read other charts.
9. Debrief verbally: What ideas surprised you? What questions emerged? How was this different from verbal discussion?

Provide sentence starters on the chart paper for reluctant writers. Allow students to draw symbols or diagrams as responses. For advanced students, require that every comment respond to someone else's idea, not just the central question.

Photograph completed charts. Analyze for depth of thinking, quality of responses to others, and evidence of perspective-taking. Note which students contributed substantively.