Scientific or lay audience? That's the wrong question

When I teach my presentation course one of the first questions I get is whether we are preparing a presentation for a scientific or a lay audience. This question is too simplistic.

I attend many scientific seminars at Stanford University and typically the audience is varied. There are audience members with expertise in the speaker's specialized sub-discipline, with expertise in related disciplines, and scientists from very different disciplines who may have techniques relevant to the speaker's research. For example, one goal at the Stanford Cancer Institute is to engage Stanford's outstanding bioengineers in cancer research.

In other words the typical scientific audience consists of members with a wide range of expertise. For example, a job talk will contain members from your sub-disciplines as well as department chairs who have little background in your work, but will ultimately decide if you get hired.

Equally important, you probably won't know who is going to show up.

Similarly lay audiences can vary. Give a presentation to a potential CEO donor from a tech company and he/she may not know your science, but they will want a hard-nosed analytical story. Other lay audiences may just want to be "wowed."

So the audience is varied and you don't know how varied. See the previous "tip" for a strategy for coping with this uncertainty.

How to address individual audiences with diverse members (hint: simple structure, even if the detail

As I discussed on other last tips, individual audience members will vary in their expertise and there will be uncertainty about who will actually come to your talk. How do you manage this?

The first step is to identify the least expert person you care about reaching. It is probably impossible to simultaneously address someone in your subspecialty and a lay person, but you can still meet the needs of a fairly broad spectrum. Prior to the talk, identify the range of people you want to reach and the least expert part of that range. For example, if you are giving a job talk, the range may span the individuals in your subspecialty to the department chair, who hasn't been in the lab in 15 years and doesn't know your specific area. You've decided ahead of time that you will not try to reach a pure lay person.

So in the above example, draft a simple narrative that the least expert target audience (department chair in the above example) can understand. Work out the language that allows you to explain that narrative to the department chair in a short amount of time. You don't need to include actual data in the narrative, but you do want to transmit the conceptual points.

Now you can add complexity and specificity that only experts can understand. But you are adding it to a structure and narrative that a broader audience understands. It is OK if the less expert audience members doesn't understand the methods underlying a slide or two because your talk is organized around a narrative they can understand. Continually connect detailed messages targeted toward the experts to the points in the narrative you've created for the generalists.

The slide's title should tell the slide's story

Don't be shy about using the title to direct the audience toward the overarching message of the slide. Every slide should have one overarching message and the title should relate that message. Remember presentations are not easy for the audience to understand so you need to guide them to the points you want them to comprehend. No need to be subtle.

The slide below shows trial accrual for six years. I could have used a bland title like, "Accrual to trials 2006-2011." However I really want the audience to focus on what happened in 2011 and want to pass a message about why there was a drop in accrual.

If this were a journal article I might have used the more objective title. In a journal article you'll have a spacious caption to explain what you want the audience to get out of the figure. The reader has more time to digest the data.