Red Light, Yellow Light
In the general clutter of everyday life, moments that need deeper thinking tend to be invisible. Students have to learn to see them. This routine focuses students on signs of puz-zles of truth, and also on typical red zones and yellow zones where such puzzles are common. To build up this sensitivity, use the routine often in deliberately different ways.

Wherever there might be interesting puzzles of truth: a text that might have questionable claims, the daily paper, TV news, political speeches, a mystery story, a math proof that might have weaknesses, playground activities and conversations, home life, pop science, potentially risky behaviors, self-critique of something one has written, etc. For settings outside of school, students can keep logs over a day to a week. Typical red zones are the editorial pages of newspapers, political speeches, playground arguments, because so many red lights occur within them. The source should be large enough to take some time, like a chapter or keeping track of rumors for a few days. That way, students have to keep alert in a sustained way, which practices their skills of noticing puzzles of truth.
Resources & Links Notes & Considerations
PZ Visible Thinking: Red Light... [Web Link] * Explain that “red lights” are specific moments with signs of a possible puzzle of truth, signs like sweeping statements, one-sided arguments, obvious self-interest, etc. Yellow lights are milder versions of the same thing.
* Naturally students may disagree on what’s red vs. yellow vs. green in particular cases. Have students explain the signs and their judgments briefly, but mainly the routine is for detecting potential puzzles of truth.
* The real way to investigate a couple of the more important red or yellow lights is to dig further into the issue with another truth routine.