According to the International Dyslexia Association, “perhaps as many as 15-20% of the population as a whole have some of the symptoms of dyslexia”. In addition, for many reasons, dyslexia and other written language difficulties are likely heavily underdiagnosed. Chances are good that many people viewing your Power BI content are impacted not only by your chart and color selection but your font choice and text size.
One of my elder children is precocious, picks up on everything, started reading at a young age, and–no matter how many times you mention taking one book off the shelf at a time– always has a pile of books out. Another child is not like that at all. Our family doctor said the former child is the unusual one and to not hold the other kids to the same level of expectation. With that thought in the back of our minds, my wife and I did not consider that the other child’s eventual trouble with reading was of much concern early on. It took an outside observer who had her own experience with a dyslexic child to help us identify some possible, specific symptoms and seek out testing and resources through the local public school system.
I bring this up because if it’s possible for two college-educated adults with multiple kids to not recognize signs of written language struggle early enough in their own household, what assumptions about your report viewers in the workplace might be incorrect by extension?
Fortunately, there are some good resources available to help people without dyslexia understand what it takes to adapt teaching, training, and parenting for someone who reads and learns in a different way than you might. My local university, the University of Michigan, has a great Dyslexia Help site that I reference. They even link to a study for Good Fonts for Dyslexia…
Back to Fonts
Power BI font selection is currently limited to about two dozen choices. These include a mix of serif versus sans serif, monospaced versus not monospaced, bold versus light, and more. While I do not have a definitive list of specific fonts–and I would love additional input from readers who live with dyslexia–there are some preferred font choices as well as choices to avoid when designing Power BI reports.
Tips for More Accessible Fonts
- Increase your font size – the default text size in many places in Power BI is 8 pt, which is too small for almost anyone, let alone people who need to be more deliberate about reading.
- Avoid italics – provide emphasis in text through other methods such as bold, increased size, a different color (with appropriate contrast), or try out some *markdown* syntax (since Power BI will not visualize markdown’s single asterisks as italics).
- Use sans serif fonts – sans serif fonts tend to be more readable than serif fonts, but increase your font size to increase readability if you do use serif fonts.
- Use fonts that provide more distinction between characters – Some fonts have characters that closely resemble others, but try fonts that have more distinction. As much as it’s popular to pick on Comic Sans, the British Dyslexia Association has useful commentary about it and other fonts in this case.
Power BI Font Choices
With some of that criteria in mind, what Power BI fonts might be better for more accessible reading?
Studies or institutions variously recommend certain fonts for dyslexia, some of which are available in Power BI:
- Arial (+arial black variation)
- Comic Sans
Other Sans Serif fonts to try in Power BI:
- Segoe UI (+bold +light variations)
- Lucida Sans Unicode
- DIN (default for a lot of labels)
Serif fonts to avoid:
- Times New Roman
- Courier New (although monospace…)
CHALLENGE: Promote Accessibility in Power BI
When it comes to report design in Power BI, it still seems like accessibility is a niche rather than foundational topic. The best way to make it more of a foundational topic is to call more attention to it. Right now, Meagan Longoria (blog / twitter) is the primary voice in the Power BI community consistently writing and presenting on it. Let’s change that. Read about inclusive design, start building concepts into your report checklists and task lists, and don’t make it an afterthought.
Thanks. But I wish that people would stop treating accessibility as optional so accessible reports wouldn’t make me unique, and that the Power BI team would introduce features that made it easier/less tedious to make accessible reports.— Meagan Longoria (@MMarie) August 25, 2020
BONUS: Reading Pattern Differences
While not the main focus of this post, Microsoft Research recently released a study and companion video on an eye tracking study for people with and without dyslexia. Although the study involves viewing web search results, it could also give you perspective on how people may be scanning your Power BI reports.
TL;DR – Results found that eye gaze scanning patterns were different. The majority of searchers with dyslexia used a Commitment scanning pattern (effectively reading, not scanning). The majority of searchers without dyslexia used the F-Shape scanning pattern.