Whether it's a major international conference, a small group meeting or a thesis defence, presentations are an essential part your work. If done well, the PowerPoint slides you use can serve as a strong visual reinforcement to the words you speak, but doing them well is very difficult.
Most people will know basic principles like, "don't put too much text on the screen", but designing good slides is a bit more complicated than that.
What you see on your screen is not what the audience will see
If you use a fairly modern laptop, the screen is probably pretty good in terms of resolution, brightness and contrast, but if you're presenting to an audience of more than about three, you won't be using your laptop screen. It's highly unlikely that the projector you use will produce as clear an image as the one you're looking at while you're creating your slides.
The room layout also plays a role. In dedicated lecture theatres with banked rows of seats, most of the audience will have an unobstructed view of the screen. Often, though, you'll be presenting in a multi-purpose room with rows of seats at the same height, meaning most people only have a partial view.
You have to bear these less-than-ideal conditions in mind if you want to be sure that everybody can see and read the content of your slides.
Avoid fancy backgrounds on your slides
I always use a plain white or black background to give maximum possible contrast with the text.White is a little easier to work with (especially if I want to print the slides) and is my usual choice, but I've experimented with black so that if I walk in front of the screen I don't get blinded by the projector.
While a subtle background colour can look OK, it doesn't add anything of value. I would avoid using a colour gradient (they may look OK on your screen, but can appear stripy on a lower quality projection), and I would especially avoid using a photo or any kind of complicated texture.
Use sans-serif typography
Because the screen is so much larger than that of your computer, you will probably be able to see the individual pixels in the image. This can make serif fonts look a bit crappy as they tend to have finer detailing at the pixel level.
Sans serif fonts are generally simpler, with less fine detailing and nice sharp edges. Arial or Helvetica are safe choices.
You also need to make sure your text is large enough to be read easily from the back of a large room. If you're sitting close to your screen you'll be able to read quite small text. But imagine you are at the back of a large lecture theatre; will that text still be legible?
One way to make sure your text is readable is to zoom out while you're designing your slides. I usually set the zoom to 40% to get a sense of what it might look like to an audience member at the back of the room. (Go to the "view" tab, select "zoom" and set to 40%). If you can't still read your text, or if it's difficult to read, it's too small.
Use the top half of the slide
Unless you are preparing a presentation specifically for a venue where you know the audience has an unobstructed view, try just using the top half of the slide.
This limits how much information you can include on each slide, but that may be a good thing if you tend to overload slides with text.
Make sure figures are legible
Make sure any text in your figures is legible. This may mean using a larger font than you would in print, and again, sans serif.
Don't use video or animation unless you absolutely have to
Sometimes the work can only be shown using video, but so often this leads to technical problems (especially if you are using the in-house computer rather than your own). If you're presenting at a conference and you absolutely have to show a video, test it before the talk (either in a break or at the start of the day), and prepare a series of still images you can use as a backup.
The built-in PowerPoint animations for slide transitions and making text fly in from the edge of the screen are pointless.
Breaking the typical PowerPoint slide format
All the points I've given so far put constraints on your design, but you can still be creative within those constraints.The typical PowerPoint format of a title followed by a bulleted list is a bit dull. It also tends to give more space than is really necessary to the title.
The same information can be presented in different and interesting ways if you break free from the typical PowerPoint layout. In the second example above, the title is made smaller and pushed up into the corner, giving more space for the important content. The vertical line adds a little bit of visual interest and ties the title and content together. In the bottom example, the division into two aspects is emphasised. Both are more interesting than the typical layout (top), without being overly complicated.
To do this, use the "blank" slide layout and use text boxes paced wherever you want the text.
Proper preparation prevents poor performance
More important than the slides is proper preparation.Practice your talk (speak out loud; scanning through the slides doesn't count) and make sure;
- it fits the time available
- you know your own slides and aren't surprised when you move to the next one
- you know exactly what your opening and closing statements are (you may want to script these)
Also remember that you probably can't include everything in the time you have. Leave some things out, and let the audience ask questions if they want more detail.