Sunday, June 26, 2011

Information design and the aesthetics of slides

I've been told often that I have nice slides. (Sometimes, alas, it's "I didn't understand most of your talk -- too technical -- but I really like your slides.") A few noteworthy general points:
  • I design slides as part of presentations (my 3500-word post on preparing presentations), so there's a reason for every slide going up on a projection screen, and that reason drives the design of the slide, defining what is important and what is not.
  • The important part of the slide must get most of the attention: highest contrast color (typically white since I prefer black backgrounds), largest type size, most readable type font (unless the type itself is informative: courier for computer code, for example).
  • Contextual information is important as well, but must be de-emphasized. Sometimes it might be the faintest suggestion (see point 4 below), but its presence adds credibility
  • I use a lot of tools to make the elements of a slide, but all the examples in this post were done using only basic drawing elements of Apple Keynote. The value is not in the tools, it's on how you use them.
  • Other than subtle gradients used purely for aesthetic reasons, all the graphic elements of a slide are there to focus attention on the important information.
Like any other information product, good information design in slides is work, so there are two main causes of poorly designed slides: first, presenters don't want to put in the effort necessary to design better slides; second, many presenters don't have an information design mindset when making slides. The first problem is a matter of motivation. The second problem is what this post is about.

The rest of the post has four examples of my slide design.

1. Quotations

Example for blog post

The elements here all work in concert: the large type and white color focus the attention on the quoted text; the large but somewhat unobtrusive quotation marks indicate that this is a quotation, and the commonality of color with the source makes it obvious where the quotation comes from.

In addition to the design elements, there's a content element that is missing from many quotations used in presentations: a complete source. Many presentations have quotes attributed to a person without the context (so that would be "Tim Oren" in the slide above). Complete sourcing shows that one is certain of one's sources and therefore not afraid to make it easy for others to check them.


2. Tables

Example for blog post

Most templates for tables in typesetting or presentation software are inappropriate for the purpose of conveying important information. For example, they make a big deal of separating the labels from the cells and add a lot of extraneous formatting automatically; as a rule of thumb, any automatic formatting will not be appropriate to a specific information design. (If it's automatic, it would have to understand the semantics of the information in order to make the appropriate design; AI isn't there yet.)

In the table above (numbers from an example in my personal blog), the labels that matter (the options being compared) are part of the cohesive information unit (which here is a column); the labels that merely describe the elements of the information unit (the rows) are de-emphasized, though in this case I chose to leave them in white to minimize unnecessary colors. The colors of the columns are not just to separate the columns (in which case I'd have used two close variations on the same color) but rather to signal that one option is good (blue) and the other is bad (red). The units of measure MM are in smaller type and 75% transparent black, which I find a less obtrusive color choice than a opaque dark grey.


3. Overlays

Example for blog post

When a lot of information is layered, like the heat map on the right in the slide above, I find it useful to have a side-by-side comparison of the original information (in this case an old print ad) and the overlaid information (in this case the heat map). These images were also on a handout distributed to the audience, which allows for deeper analysis.

I've seen many presentations where there's a build-up of elements representing an historical evolution, but the stages are never presented together on screen (or in a handout). This requires the audience to maintain the previous versions of the diagram in their working memory, something that may overtax their cognitive abilities and detract from their understanding of the story.

The heat map itself uses good information design, by representing the original image by its edges only, instead of the full-color representation; this was an option in the software which I used, not something that can be done in a presentation program.


4. Screen captures

Great Moments In Online Ad Targeting

The objective of this screen capture is to illustrate bad advertising targeting (a Porsche ad in a journal read mostly by impoverished academics). The image above would actually be the second in a set, the first having no de-emphasized text. I would put the original up, say something like "here's an example from the Chronicle of Higher Education and if we look carefully," change the slide to the one above and call the audience attention to the three elements: the journal readership, the article being about humanities, and the Porsche ad.

The only editing here was an overlay of 25% transparent white, covering the distracting elements of the page. Had I been using Photoshop, I probably would have done something to hide the picture in the upper right corner with the clone tool. Something as simple as the white-out can make a huge difference in limiting distractions, and yet so few presenters use it effectively.

The information principles of the two-slide use of this picture are simple: first establish the context and the source, then white-out the irrelevant parts to focus attention on the targeting problem.