100 Things Every Designer Needs to Know About People

How People Read

Excerpted from 100 Things Every Designer Needs to Know About People (New Riders)

By Susan Weinschenk

With adult literacy rates now over 80 percent worldwide, reading is a primary form of communication for most people. But how do we read? And what should designers know about reading?

13. It’s a Myth that Capital Letters are Inherently Hard to Read

You’ve probably heard that words in uppercase letters are harder to read than those in mixed case or lowercase. You’ve probably even heard some kind of percentage cited, such as “between 14 and 20 percent harder.” The story goes that we read by recognizing the shapes of words and groups of words. Words in mixed case or lowercase letters have unique shapes. Words in capital letters have the same shape — a rectangle of a certain size — so, in theory, they’re harder to distinguish.

The word shape theory

This explanation sounds plausible, but it’s not really accurate. There’s no research showing that the shapes of words help us read more accurately or more quickly. A psycholinguist named James Cattell came up with that idea in 1886. There was some evidence for it then, but more recent work by Kenneth Paap (1984) and Keith Rayner (1998) has revealed that what we’re actually doing when we read is recognizing and anticipating letters. And then, based on the letters, we recognize the word. Let’s look more closely at how we read.

Reading Isn’t as Fluid as it Seems
When we read, we have the impression that our eyes are moving smoothly across the page, but that’s not what’s actually happening. Our eyes move in quick, sharp jumps, with short periods of stillness in between. The jumps are called saccades (about seven to nine letters at a time) and the moments of stillness are called fixations (about 250 milliseconds long). During the saccades, we can’t see anything — we’re essentially blind — but the movements are so fast that we don’t even realize they’re happening. Our eyes look forward during most of the saccades, but they look backward 10 to 15 percent of the time, rereading letters and words.

The illustration below shows an example of the saccade and fixation pattern. The black dots are the fixations and the curved lines are the saccade movements.

An example of a saccade and fixation pattern.

We use peripheral vision when we read
A saccade spans about seven to nine letters, but our perceptual span is actually double that. In 1996, Kenneth Goodman found that we use peripheral vision to see what comes next when we read. We read ahead about 15 letters at a time, viewing the characters to the right (assuming we’re reading left to right), although now and then a saccade jumps us backward and we reread a group of letters. Although we read ahead about 15 letters at a time, we only get the meaning for part of that span. We pick up the semantic cues of letters 1 through 7, but merely recognize letters 8 through 15.

Reading music is similar to reading text
People who read music fluently use the same saccades, fixations, and reading ahead of 15 “letters” that they do when reading text.

So, Is All Caps Harder to Read Then?
We do actually read uppercase letters more slowly, but only because we don’t see them as often. Most of what we read is in mixed case, so we’re used to it. If you practice reading text in all capital letters you’ll eventually read that text as fast as you read mixed case. This doesn’t mean you should start using capital letters for all your text. Since peole are unused to reading that way, it will slow them down. And these days, text in all caps is perceived as “shouting”.

We perceive uppercase letters as shouting, but they aren’t inherently harder to read.

A Good Summary Of The Research On Uppercase
Kevin Larson wrote a great article summarizing the research on uppercase versus mixed case.

14. Reading and Comprehending are Two Different Things

If you’re a biologist, then this paragraph might make sense right away:

The regulation of the TCA cycle is largely determined by substrate availability and product inhibition. NADH, a product of all of the deydrogenases in the TCA cycle, with the exception of succinate dehydrogenase, inhibits pyruvate dehydrogenase, isocitrate dehydrogenase, a-ketoglutarate dehydrogenase, while succinyl-CoA inhibits succinyl-CoA syntehtase and citrate syntase.

If you’re not a biologist, then it might take you a long time to understand what that paragraph says. You can read the paragraph, but that doesn’t mean you understand it. New information is assimilated more thoroughly when it is plugged into existing cognitive structures.

You can calculate the readability of your text
The Flesch-Kincaid formula is commonly used to calculate the readability of text. It provides both a reading ease score and a reading grade-level score. The higher the scores, the easier the passage is to read. Low scores mean the passage is hard to read. The formula is shown below.

Flesch-Kincaid Readability Formula.

Can you Read this Paragraph?
Eevn touhgh the wrosd are srcmaelbd, cahnecs are taht you can raed tihs praagarph aynawy. The order of the ltteers in each word is not vrey ipmrotnat. But the frsit and lsat ltteer msut be in the rhgit psotitoin. The ohter ltetres can be all mxeid up and you can sitll raed whtiuot a lot of porbelms. This is bceusae radenig is all aobut atciniptanig the nxet word.

When you read you don’t absorb exact letters and words and then interpret them later. You anticipate what will come next. The more previous knowledge you have the easier it is to anticipate and interpret.

An online tool for calculating readability

Some word processing software has the Flesch-Kincaid formula built in. Or you can use this online tool to calculate the reading level of a particular passage.

I tested a paragraph from one of my blog articles. The results are shown below.

An example of readability score results from one of my blog article

Titles and Headlines are Critical
Read this paragraph:

First you sort the items into like categories. Using color for sorting is common, but you can also use other characteristics, such as texture or type of handling needed. Once you have sorted the items, you are ready to use the equipment. You want to process each category from the sorting separately. Place one category in the machine at a time.

What is the paragraph about? It’s hard to understand. But what if I give you the same paragraph with a title:

Using your New Washing Machine
First you sort the items into like categories. Using color for sorting is common, but you can also use other characteristics, such as texture or type of handling needed. Once you have sorted the items, you are ready to use the equipment. You want to process each category from the sorting separately. Place one category in the machine at a time.

The paragraph is still poorly written, but now at least it is understandable.

People use different parts of the brain to process words

Words are processed in different parts of the brain depending on what you’re doing with them. Viewing or reading words, listening, speaking, generating verbs —all of these word activities engage different parts of the brain, as shown below:

Different parts of the brain process words

What You Remember of What you Read Depends on Your Point of View
In a study by Anderson and Pichert (1978), people read a story about a house and the contents within the house. One group was told to read the story from a buyer’s standpoint, and another group was told to read the story from a burglar’s point of view. The information they remembered after reading the story differed depending on their viewpoint.


Words are processed in different parts of the brain depending on what you’re doing with them. Viewing or reading words, listening, speaking, generating verbs —all of these word activities engage different parts of the brain, as shown below:

  • People are active readers. What they understand and remember from what they read depends on their previous experience, their point of view while reading, and the instructions they are given beforehand.
  • Don’t assume that people will remember specific information in what they read.
  • Provide a meaningful title or headline. It’s one of the most important things you can do.
  • Tailor the reading level of your text to your audience. Use simple words and fewer syllables to make your material accessible to a wider audience.

15. Pattern Recognition Helps People Identify Letters in Different Fonts

People have been debating which fonts are better, easier to read, or most appropriate for centuries. One such debate centers around the use of two types of fonts: serif versus sans serif. Some argue that sans serif typefaces are easier to read because they are plain; others contend that serif fonts are easier to read because the serifs draw the eye toward the next letter. In fact, research shows no difference in comprehension, reading speed, or preference between serif and sans serif fonts.

People identify letters through pattern recognition

How is it that you can recognize all of the marks in the illustration below as the letter A?

We can recognize many variations of a letter.

You haven’t memorized all of these versions of the letter A. Instead you’ve formed a memory pattern of what an A looks like. When you see something similar, your brain recognizes the pattern.

Designers use fonts to evoke a mood, brand, or association. Some font families invoke a time period (old fashioned versus modern), while others convey seriousness or playfulness. In terms of readability, however, the font you choose is not critical as long as it is not so decorative as to make it hard to identify the letters. Some fonts interfere with the brain’s ability to recognize patterns.

The illustration below shows different decorative fonts. The first font is relatively easy to read; the others become progressively more difficult. They make it hard for the brain to recognize the patterns of the letters.

Some decorative fonts are readable, but others are not.

Learn more about font type, typography, and readability

If you’re interested in reading the research about font type, typography, and readability, check out these two great Web sites:

If a Font is Hard to Read, The Meaning of the Text Will Be Lost
Hyunjin Song and Norbert Schwarz (2008) gave people written instructions on how to do a physical exercise. If the instructions were in an easy-to-read font (Arial) people estimated that it would take about eight minutes to do the exercise and that it wouldn’t be too difficult. They were willing to incorporate the exercise into their daily workout. But if the instructions were given in an overly decorative font (Brush Script MT Italic) people estimated it would take almost twice as long — 15 minutes — to do the exercise, and they rated the exercise as being difficult to do (see below). They were also less likely to be willing to incorporate it into their routine.

People who were given instructions in a simple font estimated that the exercise would take 8 minutes to complete — about half the time of those who were given instructions in a hard-to-read font.


  • Serif and sans serif fonts are equal in terms of readability.
  • Unusual or overly decorative fonts can interfere with pattern recognition and slow down reading.
  • If people have trouble reading the font, they will transfer that feeling of difficulty to the meaning of the text itself and decide that the subject of the text is hard to do or understand.

16. Font Size Matters

When it comes to fonts, size matters a lot. The font size needs to be big enough for users to read the text without strain. And it’s not just older individuals who need fonts to be bigger — young people also complain when font sizes are too small to read.

Some fonts can be the same size, but look bigger, due to the x-height. The x-height is literally the height of the small letter x in the font family. Different fonts have different x-heights, and as a result, some fonts look larger than others, even though they are the same point size.

The illustration below shows how the font size and x-heights are measured.

How font size and x-height are measured.

Some newer font families, such as Tahoma and Verdana, have been designed with large x-heights so they are easier to read on a screen. The illustration below shows different font families that are all the same point size. Some look bigger, however, because of their larger x-height.

Large x-heights can make a font look larger.

You can calculate how large your text needs to be

To determine how large your text should be, you’ll need to consider the angle at which users will be viewing it and their distance from the screen. The illustration below illustrates this formula. If you remember your geometry, a circle can be divided into 360 degrees. Each degree can in turn be divided into 60 minutes. The illustration illustrates formulas for determining how large and how wide letters should be in order to be readable at various distances, with different font sizes, and for users with different visual acuity (20/20 versus 20/40, for example).

Formula for computing a visual angle.

Formula for determining how large text should be depending on visual acuity.


  • Choose a point size that is large enough for people of various ages to read comfortably.
  • Use a font with a large x-height for online viewing so that the type will appear to be larger.

17. Reading a Computer Screen is Harder than Reading Paper

Computer screens, Kindles, and paper create different reading experiences. When you read on a computer screen the image is not stable — it is being refreshed constantly, and the screen is emitting light. When you read text on paper the image is stable (not being refreshed), and instead of emitting light the paper is reflecting light. The refreshing of the image and emitting of the light on the computer display are tiring on the eyes. Electronic ink (as in the Kindle) mimics the appearance of ink on paper. It reflects light and holds the text stable without refreshing.

To make text on a computer screen easier to read, make sure you use a large enough font and create enough contrast between foreground and background. The illustration below shows the best combination to use for readability: black text on a white background.

Black text on a white background is easiest to read.


    Use a large point size for text that will be read on a computer screen. This will help to minimize eye strain.
  • Break text up into chunks. Use bullets, short paragraphs, and pictures.
  • Provide ample contrast between foreground and background. Black text on a white background is the most readable.
  • Make sure your content is worth reading. In the end, it all boils down to whether or not the text on the page is of interest to your audience.

18. People Read Faster with a Longer Line Length, But they Prefer a Shorter Line Length

Have you ever had to decide what column width to use on a screen? Should it be a wide column with 100 characters per line? Or a short column with 50 characters per line? Or something in between? The answer depends on whether you want people to read faster or to like the page.

Mary Dyson (2004) conducted research on line length, and combed other studies to determine what line length people prefer. Her work showed that 100 characters per line is the optimal length for on-screen reading speed; but we prefer a short or medium line length (45 to 72 characters per line). The illustration below shows examples of a short and long line length.

Line length, speed, and preference, maderalabs.com

Longer line lengths are easier to read because they interfere less with the flow of saccades and fixations
Every time you get to the end of a line you interrupt saccade and fixation eye movement. A shorter line length creates more of these interruptions over the total length of the piece you are reading.

The research also found that we can read a single wide column faster than multiple columns, but we prefer multiple columns.

If you ask people which they prefer, they will say multiple columns with short line lengths. Interestingly, if you ask them which they read faster, they will insist it is also the multiple columns with short line lengths, even though the data shows otherwise.


  • Line length presents a quandary: Do you give peole the short line length and multiple columns that they prefer, or go against their own preference and intuition, knowing that they will read faster if you use a longer line length and a single column?
  • Use a longer line length (100 characters per line) if reading speed is an issue.
  • Use a shorter line length (45 to 72 characters per line) if reading speed is less critical.
  • For a multipage article, consider using multiple columns and a short line length (45 characters per line).

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Excerpted from 100 Things Every Designer Needs to Know About People by Susan Weinschenk. Copyright © 2011. Used with permission of Pearson Education, Inc. and and New Riders.