Let's take a look at the three parts that make up the structure of any
presentation: Introduction, Body, and Conclusion.
The introduction of a talk is an opportunity to get your
audience interested in your talk as well as prepare them for the journey. You’ll want to use the brief
time that you devote to the introduction wisely. Here are some key components of effective introductions:
Entry point. What is the best way to begin the talk? Your entry point
should cultivate the audience’s interest in your topic so that they will want to pay attention to your upcoming
presentation. Often, the entry point can be a chance for you to establish the importance of your topic or
provide a “big picture” view of its significance. You might consider sharing a story from your research
experience or providing an example. There are many strategies that can be employed, but the important thing to
remember is that your entry point should be purposeful and help you begin to get the audience invested in your
Establish credibility. Although your credibility will be established in
large part from your content, it is a good idea to briefly mention your credentials as they relate to the
topic. You might mention who has sponsored your work. Or, you might discuss why are
interested in this area and feel it is important. This can take many different forms, but you should consider
sharing some information that will increase your credibility with the audience.
Preview the development of the talk. Let the audience know the purpose of
the talk and how you plan on covering the material. Audiences appreciate hearing a map of the
Structuring the body of a presentation should begin with
giving some critical thought to what your goals are for the presentation and thinking about what type of
information will need to be shared in order to accomplish those goals. It is common for presenters to
try to do too much in a presentation. Perhaps they try to cram all of the details about one year’s worth of
research into a 15 minute talk. Or, as is commonly seen at conferences, they try to pack all of the information
from a complex research paper into a short conference presentation. Typically, this type of talk is doomed before
it even begins.
You need to carefully consider what is reasonable to cover
in the time that you have, and think about the opportunities that presentation venue allows that aren’t possible in
a paper. Your presentation will be much more successful if you decide to focus on highlighting a part
of the work and giving the audience an excellent understanding and appreciation for that part. If the audience
really has a firm grasp on the part that you focus on for the talk, you can then include some discussion about its
relevance to the whole of the work, and the result is a much more satisfying presentation for an audience. Few
people enjoy a presentation that covers every detail at a breakneck pace (typically while clicking through 40
bullet filled slides). It is hard for even the most sophisticated listener to derive much benefit from that type of
presentation. Most can get more from reading the paper. Instead, you should aim higher, and use the opportunity of
a presentation to do something that a paper cannot.
To accomplish this, you must begin with thinking about what
the main idea is that you want your audience to take away and what the purpose is for your talk, and then select
points that will get you to that goal. We can think of these key points as your assertions. It is
likely that you will have one main assertion for the whole talk—this is main idea that you want your audience to
know/believe as a result of the talk. The rest of the talk will be comprised of sub-assertions—these are the areas
that your audience needs to know in order to “arrive” at your main assertion.
As you think about organizing your sub-assertions (e.g.
which should come first, second, etc.), you need to consider what your audience needs to know in order to
appreciate and understand what will come next. Presenters of technical material will often “jump right
in” to very difficult concepts, when in fact the audience might have benefitted from there being a sub-assertion or
two that came before and gave them the information that was necessary in order for them to appreciate and
understand the upcoming material. We can see this represented visually below via an “assertion tree”.
In this example, sub-assertions 1 and 2 build upon one
another, that is to say, it is necessary to understand sub-assertion 1 before you can move on to sub-assertion
2. These two sub-assertions serve to provide the information that is necessary for the audience to be
prepared for sub-assertions 3 and 4. Sub-assertions 3 and 4 are not necessarily dependent upon one another, hence
their parallel placement. But, it is essential to understand sub-assertions 1 and 2 in order to be prepared for
sub-assertions 3 and 4.
This is not intended as a recommendation of structure for
you next talk, but instead it is to get you to think about what an “assertion tree” might look like for you next
presentation. Which ideas are dependent upon one another? What order do they need to be presented in
to achieve the maximum comprehension of your audience?
The conclusion of a talk is a crucial part of the talk’s
structure, yet it is often neglected. Many presenters will just get to the end of all of the planned
content and will end rather unceremoniously with “That’s all I have.” Or an abrupt, “Any questions?” With a small
amount of effort, a good conclusion can increase retention and add some polish to your talk. You should view your
conclusion as your final chance to reinforce what you want you audience to take away from your presentation and
reach any audience members that may have drifted off.
There are three goals that you should think about achieving
with your conclusion:
Review. You should recap the key ideas that you covered in the
presentation as a way of brief review for your audience.
Final appeal. Tell the audience what you hope
your talk has shown them; essentially it is your final reminder of your main assertion.
End with impact. You might consider an appropriate final
thought for the talk. A well-planned closure line can wrap a presentation up very smoothly. Of course, you
should follow up with asking for questions.
This speaker’s introduction has several strengths that stand
out. The first is that she establishes her credibility as a speaker on this topic well. She
mentions her experience in working at a plant and that she saw first hand some of the issues with
O-Rings. Secondly, the main assertion for the talk is clear: Silver plated C-Rings
should replace O-Rings in nuclear power plants. Another key strength is that she very clearly previews for the
audience what the talk with cover: 1) The function of the control rods in a plant, 2) How O-rings are relevant to
that function, and 3) Why the silver coated C-Ring is more effective than the O-Ring. This prepares the audience
for the information that is coming and provides a glimpse at the speaker’s sub-assertions.
The Body (1:17-8:15)
This is how an assertion tree for this talk would look:
The main structural strength of this presentation is the
speaker’s ability to highlight the most important pieces of information that the audience must know in order to
understand the main assertion of her talk (Silver-plated C-Rings should replace O-Rings in nuclear power plants).
She chooses her sub-assertions by asking herself what the
audience needs to know in order to understand her main assertion. This is an important
technique that presenters of technical material should consider to make their talks more effective. It is often
tempting to want to tell the audience everything about a topic. As a result, the audience can become
buried in details that cause them to lose sight of the main message.
Let’s consider the choices that this speaker
made. She could have decided to explain a nuclear reaction in much more detail and she could have then
explained all of the inner mechanics of a Boiling Water Reactor before explaining the control rods. If she had done
this, her talk could have very quickly become unfocused. Instead, this speaker knows
that the key idea that the audience must understand in order to support her main assertion is the function of a
control rod in a nuclear power plant. Once we have this piece of information, we are then able to understand why it
is a concern if the control rods don’t function properly. We are now prepared appreciate the significance of the
O-Ring’s impact on the function of a control rod.
Ultimately, each of these sub-assertions gives the audience
the ability to understand and appreciate the main assertion of the talk: Silver coated C-Rings should replace
O-Rings in nuclear power plants.
As this speaker concludes, she provides a
reminder of the benefits of the C-Rings over the O-Rings because this is the information that she wants her
audience to remember. Finally, to close the talk, she provides the audience with a look at the “big
picture” importance of keeping nuclear power plants functioning well. This is effective because it allows the
audience to situate all of the information that they just learned into a more broad perspective. It is easier for
an audience to remember information if they understand the broader importance of it. Smaller details can be
forgotten, but if those details are woven into a fabric that the audience already has an understanding of, then
those details become much more important.
This presentation employs a
clear structure of a main assertion and subsequent sub-assertions to lead the audience through the presentation.
We can see this represent here visually with an assertion tree:
Let’s take a look at some other structural elements in this
A strength that we can see in the body (1:17-9:03) of
this presentation is this speaker’s clear organization and transitions from one key point to the next.
Transitions are important because they help the listener to know where they are going, but also where they have
been. Most effective transitions summarize the point that has just been discussed and then preview for the audience
what is coming next. This is helpful to the audience because it helps them see how the argument is progressing, but
also it helps to “bring back” some listeners who might have become distracted because it is a signal that a new key
point is coming. Transitions also help the presentation flow well as they connect one point to the next.
There are five transition points in this presentation that
connect the parts of the presentation together.
1. “So to start with, I would like to talk about the
blood shortage itself.” (1:17)
2. “Clearly this is a huge problem, but what can we do about
3. “Now that we have talked a little bit about how scientists
can create red blood cells from stem cells, I would like to talk a little bit about the ethical debate regarding
4. “Now that I have touch on the ethical debate regarding this
stem cell research, I would like to talk further about how we can use stem cells to end the blood
5. “Just to recap briefly…” (9:05)
You should consider how to incorporate transitions into your
next presentation. This small component is fairly simple to include, but it can have a bit impact on
the flow of your presentation, as well as your audience’s ability to follow your talk.
to mention about this presentation is that this presenter anticipates the potential bias of his audience towards
this controversial topic. This presenter acknowledges and discusses the ethical debate concerning
stem cell research (6:15-7:25). Many presenters of science and engineering will deal with controversial
subjects. Some presenters choose to ignore the bias of the audience, but this is rarely a good strategy and it
often has the potential to ruin a presentation. When an audience has concerns, those concerns are not going to
just go away because the presenter “steamrolls” them with information. Instead, it is best to acknowledge the
controversy and the concerns of the audience.