I recently read Cole Nussbaumer Knaflic’s Storytelling with You. Building on the success of Cole’s previous books on data visualisation, Storytelling with You contains detailed strategies on how to plan, create, and deliver compelling presentations. As I have a talk coming up at DataEngBytes Brisbane, I figured it was worth reading to sharpen my presentation skills.

While the book contains many tips that I am already familiar with (e.g., overloading every slide with dense bullet points is not a good idea), one thing that was new to me was the rule of thirds for composing images. As described on Wikipedia, the rule of thirds “proposes that an image should be imagined as divided into nine equal parts by two equally spaced horizontal lines and two equally spaced vertical lines, and that important compositional elements should be placed along these lines or their intersections.”

It’s nice to have rules to follow, but it seems like the rule of thirds was pretty much made up over two hundred years ago (see the Wikipedia article for historical details). Indeed, a recent study found that “for photographs that were rated as highly aesthetic and for a large set of paintings, calculated ROT [rule-of-thirds] values were about as low as in photographs that did not follow the rule of thirds.” And that “the rule of thirds seems to play only a minor, if any, role in large sets of high-quality photographs and paintings.” Similarly, an article from Adobe also states that the “rule” doesn’t have to be followed for a photo to be successful.

That said, Cole notes that when using an image that fills the slide, following the rule of thirds leaves a bit more space for overlaying text. For example, I accidentally benefited from using a stock photo that followed the rule back when I built a recommender system for music from Bandcamp (see the cover photo there for a partial snapshot). In general, it’s worth being mindful about the composition of slides and other visual elements, which is where knowledge of rules of thumb can be useful. But when it comes to things that can be tested, like high-traffic websites, rigorously experimenting with positioning and composition may be the best approach.