Effective Visual Aids
Tools like PowerPoint make it very easy to thoughtlessly copy-paste figures into a slide deck. Unfortunately, this can obscure the point you're actually trying to make, decrease readability of your slides, and just generally overwhelm your audience. Therefore you need to critically evaluate the visuals you plan to use.
The point of this article is to explain efficacy of visual aids in terms of content. To read more about design, click here. As a side note, I'm using the term "visual aid" in a broad sense that could refer to an individual figure, a set of bullets, an entire slide, or any other self-contained visual element.
Start with Strategy
You can't adequately evaluate your visual aids if you haven't really considered the context in which they'll appear. A visual aid may work well in one presentation but be totally inappropriate in another. So start with a little strategic planning by considering these three questions about your talk in general:
- What TYPE of presentation is it? (e.g., poster, seminar, lab meeting, etc)
- Who is the AUDIENCE? (e.g., faculty, peers in your sub-field, broader scientific community, etc)
- What is your GOAL? (e.g., get feedback on your results, persuade people to give you funding, etc.)
I call these the TAG questions, and I use them for every presentation I give. You can read more about strategic planning here.
What's the Point?
With this strategic plan in mind, now turn your attention to each individual visual aid and identify its PURPOSE in the context of your talk. The more specific you can be, the better. So don't just say "The purpose is to show my results." Instead, specify something like:
"The purpose of this diagram is to explain the key elements of my experimental setup."
"The purpose of this graph is to demonstrate that our approach improved efficiency"
"The purpose of this slide is to show that the model successfully reproduces real-world phenomena."
Then, from this purpose, identify ONE key takeaway / central message. I.e., what do you want the audience to take away from this slide/figure? The answer should be expressed in a single sentence. If you're struggling to boil down the key takeaway this much, you're probably not being specific enough about your purpose.
Some examples based on the purposes above:
"The key elements of my experimental setup are a laser, a camera, and a clamp to hold the samples."
"The percent efficiency with our methodology was significantly greater than control across all tested frequencies."
"The model simulations display the same key features as the real-world observations."
Here it's also important to consider whether the key takeaway for this visual aid aligns with the overarching central message of your entire talk (read more about developing a central message here, under "What You Say"). If you're using the Pyramid Principle to structure your ideas, you can treat each visual aid as a bottom-tier detail.
Usefulness + Clarity
Lastly, for every visual aid, consider these two questions:
- Is it USEFUL?
A cardinal rule of presentations: ONLY INCLUDE WHAT YOU'LL ACTUALLY TALK ABOUT. It's extremely common for presenters to include extra visuals that they never discuss. Don't be that person. In addition, your visual aids should add value by complementing what you say in your voiceover. The visuals should NOT be completely redundant with your spoken words (so don't write out complete sentences!!).
- Is it CLEAR?
Each visual aid should be as simple as possible to accomplish its purpose. That means removing extraneous details and perhaps modifying the design a bit (read more about that here). And make sure the visual is sufficiently good resolution and large enough to be seen from the back of the room.
A great visual aid is easy for the audience to digest quickly and enhances your voiceover instead of detracting from it. In practice, you probably won't go through the exercises above for every single figure and slide in your presentation. But if you do it a few times, the process can start to become automatic. And, when you're struggling with a slide that's too busy, or you're undecided about whether or not to include a particular piece of data, the questions above can guide you to make more effective decisions.