Over the Threat-Level Rainbow

September 11, 2001 didn’t change everything, but it changed a lot. We got a big new federal agency, the Department of Homeland Security; and one of the first things it gave us (aside from qualms about a name that evoked rhetoric about “das Vaterland”) was a system of communicating “the threat level” using the rainbow.

Before I say anything more, a word to the communication professional who was given the job to develop a system for telling us about the terrorist threat level in a clear way:
I am certain that what you came up with was great to start with, and that people way up your chain of command - people with communication skills on a par with those of compost heaps - told you to say it their way. We'll never get to see how you rose to the challenge so masterfully, but we know what it's like to be edited by a committee of people who couldn't write their way out of a wet paper bag with properly sharpened pencils. This post is not about you, it's about them. You can show them this post if you think it will help.

The threat-level rainbow instantly became joke material.
Why?

There were a lot of reasons, and all of them provide lessons for technical communicators. To recap, here ‘s a link to a page with a graphical explanation of the system. This is on the Department of Homeland Security web site:
http://www.dhs.gov/files/programs/Copy_of_press_release_0046.shtm

Here's the text in the graphic:

• (Red section) SEVERE: Severe risk of terrorist attack
• (Orange section) HIGH: High risk of terrorist attack
• (Yellow section) ELEVATED: Significant risk of terrorist attack
• (Blue section) GUARDED: General risk of terrorist attack
• (Green section) LOW: Low risk of terrorist attack

I think this graphic probably sent 90% of technical communicators up in a tight spiral. We had a lot of fun trying to top each other in pointing out what was wrong with it, because that’s what we do. But now that the DHS has decided to retire the threat-level rainbow, let’s see what lessons we can take from it and apply to our own work.

What should we do better?

Accessibility.
The colors were only meaningful to people with full-color vision. Although around 90% of the sighted population has full-color vision, using colors as the main keywords excluded TENS OF MILLIONS of Americans.
Do it better: Color is great, but if your audience might include people who can’t perceive it accurately, don’t use it as the main way to make your point.

Expectations.
As kids, we learn that the color sequence in the rainbow is red, orange, yellow, green, blue, purple. When we see red – orange – yellow, we expect the next color to be green. The threat-level rainbow breaks our mental model: After yellow comes blue. So lots of people had trouble remembering what blue meant.
Do it better: Choose metaphors and symbols that are intuitively clear.

Metaphors that work.
The reason the threat-level rainbow goofs up green and blue is almost certainly that green means everything is OK, and that definition is not open to renegotiation. Rather than stopping and finding a visual metaphor that provided a meaningful sequence of five elements, they broke the metaphor after the third of five messages.
Do it better: Broken metaphors don’t help your audience. If your metaphor breaks at any point, find one that works better.

Intuitive scale.
Most people would recognize hot – warm – tepid – cool – cold as a five-point scale; but the keywords severe, high, elevated, guarded, and low don't form an obvious sequence. Low isn’t the opposite of severe, high isn’t the opposite of guarded.
Do it better: Don’t invent a scale; find one that expresses the continuum you’re talking about.

Appropriate scale.
The confusion about what the blue and green levels meant was moot, because the USA has never been at either level.
Do it better: This is akin to explaining “DANGER” notices in a manual that doesn’t have any. Don’t. Who has time to do work that won’t be used?

Tight editing.
Take another look at the list of threat levels. Why say “HIGH: High risk of terrorist attack” when you could say “HIGH risk of terrorist attack” instead? And what about “GUARDED: General risk of terrorist attack” – what does that even mean?
Do it better: Phrase things consistently, use as few words as you can get away with, and make each word convey your meaning precisely.

Warnings we can respond to.
Any time you’re at an airport in the USA, sooner or later you’ll hear an announcement that says the threat level is orange. George Orwell and Robert Anton Wilson would be proud: It’s an announcement calculated to make us tense up inside, but there’s never any advice about how to identify, evaluate, respond to, or prevent threats.
Do it better: If you’re going to warn people about a hazard, tell them how to stay safe.

We could delve into the implications of setting up a multi-level system to inform us of threats and then leaving the threat level unchanged for five years, but that’s outside the realm of technical communication.