First, the Audience

There is a misjudgment nearly every speaker makes — even those who have done it many times.

We forget that the audience does not know what we take for granted.

When we were assembling John Mills’s TED talk — the story behind Watch Duty, the wildfire-alert system — we rehearsed one passage again and again:

“On the eleventh of August 2021 we launched Watch Duty…”

“Eight days after launch…”

John spoke those lines dozens of times. Clean, confident, precise.

Then, one afternoon, in the middle of stitching the talk together, we realised:

We had never told the audience what Watch Duty was.

We had laid out the problem — the failures of the official wildfire alert systems.

We had set the stakes.

We had built the tension.

But the joining tissue, the connecting line, was missing:

Watch Duty is an alerting application.

The very solution to the problem we had spent minutes establishing.

Such a simple detail. Such a critical one. And we had walked over it without a glance.

This happens constantly.

We live inside our field, our work, our vocabulary. We assume our references are universal. What feels like obvious context to us is often quite invisible to those listening.

In a five-minute talk, one cannot afford that kind of oversight. Every second is counted. Every word either builds clarity — or undoes it.

A common question follows.

How does one decide what to keep, what to remove?

The classical rule:

Is this signal, or noise? Does this serve the message, or distract from it?

To which I would add a quieter, more pointed test:

Is this essential new information — or insider knowledge?

And the only way to answer that, honestly, is to have defined one’s audience with precision.

Peers?

Investors?

Colleagues from neighbouring teams?

A technically literate room?

A general audience who has walked in cold?

One subject. One speaker. An infinite number of possible talks — depending on who is listening.

For John’s talk, we made a decision. We assumed nothing. We assumed no one in the audience had ever heard of Watch Duty. Some had. Some used it. But to leave a single person confused was unacceptable.

So the line, refined, became:

“…embarked on an eighty-day sprint to build a non-profit alert system, called Watch Duty.”

Non-profit. Alert system.

Three small words.

But they made the bridge the audience needed — the bridge we had nearly forgotten to build.

—

Before you next stand to speak, take a moment to look at those who will be listening.

Who, exactly, are they?

And what — that you take for granted — would they need you to say?