The work of a public speaker is never done. You can never complete your expertise – true knowledge of a subject is the work of a lifetime. You can never finish perfecting your presentation – even Martin Luther King’s “I Have a Dream” speech had some slips of the tongue, and it is generally considered one of the best speeches of the last century. It’s too early in this century to talk about the best yet, but whatever it is, you can be sure it will be imperfect.

And you can never connect perfectly with an audience. Attention is partial, and even if you’re perfectly present, only some imperfect percentage of the audience will be. Communication is always less than complete – noise always attends the signal, and the work is never done.

But if you do well in three areas as a speaker, you can at least take the rest of the day off, content in the knowledge that you did your job. So what are these three tasks?

First, structure. It’s not enough just to dive into your topic and share your expertise. It’s also your responsibility to give your audience a way to think about what you’re telling them. This is known as a taxonomy – a structure. It doesn’t have to be complicated: “Five Ways to Think about the Regenerative Possibilities of Bees’ Knees”; “The Three Kinds of Labrador Retrievers and Why All of Them Are Annoying”; “The Six Secrets to Internet Domination” – and so on.

If you’re not providing your audience with not only knowledge, but a bit of knowledge about the knowledge – the rules of the game – you’re not doing your job.

It’s essential to help the audience retain what you’re telling them to give them a structure to remember your expertise.

Here’s an odd rule: you have to give the audience one taxonomy – and only one. As soon as you dive into a second – “The Four Ways in which the First of Five Methods for Increasing Lifespan Can be Applied” – a subset of your taxonomy, in other words – the audience begins to lose focus. Our brains simply can’t handle more than one knowledge set at a time. We deeply resent, and tune out, speakers who try to foist more than one on us.

Second, Emotion. Different audiences want different things – the larger the audience, the more it wants to laugh, and the smaller the audience, the more it wants to cry – but all audiences want to do both. If you don’t get emotional with them, they won’t remember anything at all. That’s how we remember: we attach emotions to facts and incidents. Without the emotion, we don’t do any attaching.

It’s perfectly possible to attend a business meeting that is devoid of emotion and not remember anything about it a week later. That’s not a senior moment – that’s a human moment.

Third, Depth. Speeches are not the place for much depth, but you should give your audience some sense of what it means to go deep in some aspect of your expertise, even if it is only to say, “That’s what X looks like, but I only have time to discuss a couple of aspect of it.” There, you’re simply hinting at – adumbrating – the rest of the knowledge. That’s OK, but even better is to tell a story which sketches out the deeper expertise you’re reporting from. That helps the audience evaluate and understand what it has learned, and what it hasn’t.  It needs to know what the depth of your field looks like, as well as the taxonomy.

Three tasks to complete – it won’t make for a perfect speech, but it will make for a satisfactory one, and you then get to head to the bar with the knowledge that you’ve completed your day’s work.