Tank, Bucket and Trough:
Secrets to presentation success

To improve your ability to present your ideas effectively—to inform and/or persuade any audience—it’s important to understand two ideas.

The first is that the true value of any presentation can only be found in what comes out of the presenter’s mouth. The second is that the only thing that matters is how information goes out of the presenter’s mouth into the long-term memory of individuals attending the presentation.

Believe it or not, tapping into how people listen is the secret to presentation success.

How listening works

Listening involves both working memory (sometimes incorrectly called short-term memory) and long-term memory. When we listen to someone with the
Water pouring from a tap as a metaphor for presentation success
intent of understanding and retaining what they’ve said, we take small amounts of information into working memory. From there, we move each snippet of information to long-term memory—to find or create a place for that information in our existing cognitive framework so we can retain it and use it later.

When working memory is engaged with long-term memory, listening stops. As humans, we can either listen to what someone is currently saying, or we can process what the person has just said. We cannot do both; we cannot listen and think at the same time.

Any information not moved from working memory to long-term memory will be lost. It will not be retained, regardless of the best intentions of the person attempting to communicate, or how important that information is to the person or people attempting to listen.

If you’ve ever attended a fantastic presentation that you felt provided incredible value while you were there, but shortly after the presentation can’t remember a darn thing the presenter said, you’re familiar with what happens when working memory is overloaded. Nothing is retained; even the value you thought you were receiving cannot be later recalled.

The hitch to this process is that working memory is overloaded, which can happen very quickly, nothing is retained. Information spills out, never to be retrieved.

One Bucket at a Time

The best way to understand how this works is to think of the sender of information (the presenter) as someone with a tank full of water that he or she would like to get across to a series of troughs, which represent the long-term memories of individual audience members. The only thing that has a chance of being remembered by the audience is water that makes it from the sender’s tank to the receiver’s trough.

The water has to be transported from tank to trough one bucket at a time. This represents how working memory takes small amounts of information to long-term memory, where it can be recalled later.

The audience fills their small bucket with information from the presenter. When the bucket has reached its limit, the bucket is taken to the appropriate trough and emptied.

Any water spilled while the bucket is on its way to or from the trough is lost forever. The process is repeated until the tank is empty or time runs out.

There are a couple of twists to this analogy. First, each bucket can only be filled at a conversational speed. If information comes too quickly, a spring releases at the bottom of the bucket and everything spills out, never to be retained. Working memory is overloaded.

Second, the spring gets sprung if the information is filled past a specific line on the bucket. Again, working memory is overloaded.

Either of these—the information coming too fast or too much information—overloads working memory. The presenter’s information never makes it to the trough and is lost forever.

You fill too quickly if you don’t pause during your presentations. The audience needs time—in silence—to move each small piece of information from tank to trough.

You fill past the line by showing the audience any form of written information while talking to them. Every slide that’s shown or used when someone is talking—every situation in which there’s something for the audience to read, to think about, to decode or to decipher—comes with a cognitive cost that results in working memory being overloaded. When working memory is overloaded, very little (if anything) makes it to the trough.

As researcher Dr. Christoph Wecker puts it, there is a “speech suppression” effect of PowerPoint. His research demonstrates that, when slides are used—even using what he calls “concise” slides that are less cluttered and fewer in number than the vast majority of slides you’ve seen in your life—the audience does not hear large portions of what the speaker is saying.

If you want to improve the amount of information that makes it from your tank to their trough—if you wish to increase your ability to inform or persuade any audience—you will be most successful if you do it one bucket at a time.

Don’t deliver a presentation to your audience. Have a conversation with them, and they will better retain and use your ideas long after you have left the room.

Media training consultant Eric Bergman beside his motorcycle with the skyline of Toronto in the background
Eric Bergman has been helping his clients embed their ideas in the minds of audiences through speeches and presentations for more than 35 years. Contact him if you’d like to take your communication skills to the next level through his presentation skills seminars, workshops and one-on-one coaching.