This resource is an archived version of the Readability Guidelines.
New wiki is at: readabilityguidelines.myxwiki.org
Go to the Capitals page.
Recommendations
Capitalised words are not easy to read for multiple reasons. One is that people are much more used to reading words in lowercase letters, so those are what our brains find easiest to scan and instantly absorb.
1. Do not capitalise whole words or phrases.
2. Use sentence capital case in headlines and subheads.
3. Use sentence case for buttons.
Exceptions are proper nouns, and:
- job titles when following the person's name
- titles like Mr, Ms, Dr, the Duchess of Cambridge (the duchess at second mention)
- buildings
- place names
- brand names
- when referring to a specific faculty, department, institute or school
- names of groups, directorates and organisations: Affordable Housing Action Group
- titles of specific acts or bills: Human Rights Act (but use ‘the act’ or ‘the bill’ following first use on a page)
- names of specific schemes known to people as proper nouns would be: Right to Buy
- specific select committees: Public Administration Select Committee
- header cells in tables: Annual profits
- titles of books, for example, ‘Content Design’
- World War 1 and World War 2
Usability evidence
’The science of word recognition’, Mike Jacobs, 2003
GOV.UK style guide UK Government website
How Capital Letters Became Internet Code for Yelling, Alice Robb, The New Republic, 2014
Many, many more sources under the wiki Discussion tab for this topic.
I find people love to cap everything and then when I say it disrupts reading they say: "good. I want them to take note of the programme etc". I see the point they are trying to make but the number of caps on a page and the amount of slowing down (if there's a lot of it) I *think* impacts comprehension. I have seen more regressive reading (where your eyes jump backwards) if there's too many caps. However, I can't find research to support this. Does anyone know of anything?
I'm struggling to find any research which shows that capitals have an impact on comprehension - could it be that this is just a matter of style, like other things we collectively seem to believe?
I've attached photos of pages from the Oxford English Grammar setting out its position on capitals. And there's not a lot.
There's now a pic of Fowler's Modern English Usage on capitals, which is helpfully prescriptive.
I've also attached a snippet from David Crystal's Encyclopedia of Language, in which he writes about how capitalisation is often a cultural decision - as opposed to being innately or naturally correct.
I've always personally found capitals harder to read, and found the lack of variety in all caps words or phrases (no descenders or ascenders to give words distinct shapes) a problem for scanning. When I've tested the content for users, they interpret all-capitals as shouting. But they don't seem to struggle with title case in headers or names, if they're in a context where they expect to see it (like job roles or service names).
But in trawling the internet looking for evidence either way, I actually found a study that suggest that upper case may be more legible because it stands out more. They conclude that upper case letters are more legible at a distance and are quicker to read.
Letter case and text legibility in normal and low vision, Vision Research (2007)
They argue that "apart from economic considerations of how much space a given sample of text occupies, letter size determines legibility for low vision readers and for those viewing visually small text; and when point size is fixed, upper-case text is simply more legible, albeit less aesthetically appealing, than lower-case."
I've also seen a reference in the results of a Nilsson eye tracking study that upper case letters are eye catching. That may be a good thing or bad thing, depending on context and whether you want their eye to be caught by that particular word.
[https://www.nngroup.com/reports/how-people-read-web-eyetracking-evidence/]
"Eye-catching text elements such as capital letters and bulleted lists can create interest. People looked at 29% of words that appear in all capital letters."
Thanks Sarah for reminding me to dig into the NNG eye tracking research. Here are the edited highlights from their findings.
We know that people often scan, rather than read, online - and that there are different patterns for scanning, including the F-shape. As the research puts it: "The acts of scanning and reading are quite different. Reading includes looking at most words in chronological order in a section or on an entire page. But when scanning, people look at words, headings, or sections of pages, often out of order, fixating on only some of the words, not entire lines of text."
Scanning leads to a "spotted pattern" for consuming a web page, with people looking out for some elements including:
• bolded words
• underlined words
• words in colors other than that of the main body text color
• numbers written as numerals
• words in all capital letters
• long words
• words or initials that begin with a capital letter, appearing within a sentence
• words in quotation marks
• words with trademark, copyright, number power, or other symbol
attached
• words that are shaped like specific words they are looking for
• words above, below, or beside any of these elements
This is also true on search results pages, where "people tend to look at words that they used in their query, words that are links, and words that are bolded or in all capital letters". Although: "The use of all capital letters attracts attention, but it can also detract from credibility in some cases."
Thanks Karl, I could only see the summary so good to see some detail.
What I take from this is that capital letters draw the gaze. And according to a study, they are more legible at a distance and quicker to read. That might be useful for people designing posters or trying to grab the user's attention.
The other thing I wanted to consider though was the 'yelling' element that I've heard from users. Some people I've spoken to feel all-caps is more aggressive, sort of like making something red, bold and underline.
I found this news article that talks a bit about it: Netiquette of Capitalisation, The New Republic (2014)
It talks about how capital letters fill the space and crowd out other messages, are associated with monuments and other grand things, and are often used in literature to convey volume and aggression.
Some academic reesearch that's interesting but not sure it will help in conversations about capping up random words though:
https://www.researchgate.net/publication/271957284_Case_alternation_impairs_word_identification
" A straightforward word-identification experiment revealed that case alternation does, in fact, lead to a large impairment of word identification, as would be predicted by models of word identification based on multiletter visual features."
https://www.jstor.org/stable/1421250?seq=1#page_scan_tab_contents
The Effect of Type Size and Case Alternation on Word Identification (1969!)
http://journals.sagepub.com/doi/pdf/10.1080/713755978
Neuropsychological evidence for case-specific reading: Multi-letter units in visual word recognition
(Just reading this one now but looks interesting.)
https://github.com/humanmade/hm-pattern-library/issues/75
Are all-caps headings bad for accessibility?
Apparently: "Firstly, some screen readers read capitalized text letter-by-letter. And this occasionally even occurs when the HTML is in sentence-case and the CSS forces the capitalization."
https://uxplanet.org/why-letter-casing-is-important-to-consider-during-design-decisions-50402acd0a4e
I don't agree with all of this (like caps in buttons) but it said:
“When text is set in all capital letters, reading speed is slowed about 13 to 20 percent (Breland & Breland, 1944). Reading speed is optimal when uppercase and lowercase letters are used (Poulton, 1967; Rickards & August, 1975). When extra emphasis is needed, bold has been found to be a better cue than uppercase (Coles & Foster, 1975).”
Can't find the Poulton study on line at the moment. Often cited though. Must be somewhere.
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.513.2691&rep=rep1&type=pdf
This is about paper vs computer but said:
When the task involves reading continuous text from paper, however, there is generally superior performance with lowercase letters. For example, Tinker [1955] reported that text in all uppercase letters retards reading speed by 10.2-14.2%
And a stack I don't have time to get through as I am near the deadline :D
https://link.springer.com/book/10.1007%2F978-1-4684-0994-9
Late last night I found a few sources of information to consider, some of which contradict one another:
https://medium.com/@jsaito/making-a-case-for-letter-case-19d09f653c98
"According to Google’s first UX writer, Sue Factor, one of the main reasons why Google decided to go with sentence case was because it was just easier to explain to designers and engineers. In a product interface, it’s not always clear what’s considered a 'title.' Is a tab name a title? How about a settings checkbox? Or a confirmation message?"
I LOVE that, it's often the argument I make at my organization. If we capitalize this, and that, and this, where does it stop? I also think capitalizing 'titles' can lead to a false sense of importance in content. But that's assuming capitalization would be the main hierarchical visual cue (usually not so).
This one complicates the topic (same article already referenced by Sarah Rach):
https://www.sciencedirect.com/science/article/pii/S0042698907002830
"Reading speeds were higher for upper- than for mixed-case text at sizes twice acuity size; at larger sizes, the upper-case advantage disappeared. Results suggest that upper-case is more legible than the other case styles, especially for visually-impaired readers, because smaller letter sizes can be used than with the other case styles, with no diminution of legibility."
and
"…at great viewing distance (as simulated by small visual size), upper-case text is more legible, even in a font with a relatively large x-height, which might be expected to minimize upper- and lower-case differences. Other fonts, which typically have smaller x-heights, might be expected to show upper-case text to have even greater relative legibility. Contrary to Tinker’s findings, and the conventional wisdom, is the result that upper-case text is more legible in terms of reading speed, for readers with reduced acuity due to visual impairment, and in normally-sighted readers when text is visually small."
This makes me think that context really, really matters when it comes to caps and how they are used.
http://csjarchive.cogsci.rpi.edu/Proceedings/2013/papers/0462/paper0462.pdf
"Subjects' eye movements were recorded while they read sentences for comprehension. Sentences were presented with capitalized nouns—in agreement with German spelling rules—or completely in lowercase. Overall reading speed was not influenced by the manipulation of capitalization, but fixation durations were affected by the interplay between capitalization and the word classes of the fixated and the succeeding word. As expected, fixations were shorter for capitalized than lowercase nouns, but unexpectedly they were longer when the upcoming word was also a noun. This modulation was reduced when all words were printed completely in lowercase. We interpret the results as evidence for distributed processing across several words."
https://www.mity.com.au/blog/writing-readable-content-and-why-all-caps-is-so-hard-to-read
"When we read, we don't actually look at every letter in a sentence, but actually the shapes of the words. When text is in All Caps, the height of every letter is identical making every word an even rectangular shape, forcing us to read letter-by-letter, reducing our reading speed. …All Caps can be useful for reducing the focus on text." - with visuals to explain
This one also throws a wrench:
https://docs.microsoft.com/en-us/typography/develop/word-recognition
"Word shape is no longer a viable model of word recognition. The bulk of scientific evidence says that we recognize a word's component letters, then use that visual information to recognize a word. In addition to perceptual information, we also use contextual information to help recognize words during ordinary reading, but that has no bearing on the word shape versus parallel letter recognition debate. It is hopefully clear that the readability and legibility of a typeface should not be evaluated on its ability to generate a good bouma shape."
I wonder if there is a threshold we could define about the number of words in sequence in all caps, title case, sentence case, or combo, that determines readability?