(How) does capitalization affect readability
TLDR
In short, given the following two options:
- This is sentence case
- This is Title Case
Has any research been done into which one is more user-friendly, especially considering dyslexia and other reading disabilities?
Long story
I've been trying to find the best way to capitalize headings, menu items and other UI features.
After reading several blog articles about sentence vs title case, I've yet to find research results that show how this capitalization affects users. Questions that I'd love to weigh against each-other include:
- Which option easier to scan
- Is there a favorite for users with reading disability
- Do form factors affect this issue (font-size, color, font)
- Does culture affect this at all
- Does either option affect reading comprehension
- Does it affect retention
I'd love to cut out all the "user preference" reasons and get down to finding why users prefer specific capitalization methods.
For example, I know I prefer Sentence case over Title Case because it's quieter on my eyes. I could reason that this is because I'm used to most body text being sentence case. You wouldn't write an entire book in Title Case, for example.
While I find explanations like this useful, they are not conclusive, as they're not based on research. So I'd love to get some actual numbers to go with this, if at all possible.