In 2008, I ran my doctoral dissertation research study at IBM, where I worked.

I emailed ~1,000 IBM employees asking them to take part in my research. I remember one response in particular. It had nothing to do with my actual study.

A person asked why my email looked a certain way. They noticed that the paragraphs in my email were more narrow than their other emails.

Instead of filling the screen, the text only went 15-20 words before going to the next line.

“Why is that?” This person asked.

Line length study

A few years earlier, in 2005, my IBM colleague Peter Orton studied the effects of line length on reading and learning.

The study used eye tracking software. Its goal was to better understand how well people read digital text.

Some study participants read paragraphs 9 inches (23 cm) wide. This is like many websites and email application layouts.

Others read the same paragraphs but at 5 inches (13 cm) wide. This is like many printed books and magazines.

The results were interesting.

People read faster and retained more when reading narrow paragraphs.

Why?

👀 Eye movements

A few things happen when you read a paragraph of text.

• Fixation: your eyes make a short stop

• Saccade: your eyes make a small, quick movement forward

• Regression: a backward saccade

• Return sweep: your eyes go to the next line

Eye tracking results

Here’s how narrow paragraphs help you read faster and retain more.

Regression

Wide paragraphs have more regressions than narrow paragraphs. We go back and re-read text more in wide paragraphs. This takes more time and affects how well you remember the information.

Fixation and return sweep

Wide paragraphs have longer return sweeps than narrow paragraphs. Your eyes have to travel farther to find the next line. Sometimes, you read the wrong line. This results in an extra fixation, which takes longer.

The challenge with digital text

Unlike in print, digital text line length can vary depending on the device you use.

Here are screen widths of my devices:

• 2.25” (phone, portrait)

• 4” (phone, landscape)

• 6” (tablet, portrait)

• 10“ (tablet, landscape)

• 11” (laptop)

• 23” (desktop)

Here’s what a long email on a 2.25” wide smartphone looks like:

Here’s the same email in full screen on a desktop:

Reading this email in full screen on a desktop would take you longer and you’d remember less of it.

Practical takeaways

Use these 4 simple techniques to read email faster and retain more:

1) 10-20 words per line

The ideal line length is more about number of characters and words than a ruler length like 5 inches. Stay in the range of 50-80 characters, or 10-20 words per line. That’s about 1 sentence. Resize your reading window to be in this range.

(I adjusted the font size in this week’s newsletter. See if you can tell the difference in words per line.)

2) Read in landscape mode on a smartphone

Smartphone reading presents a unique problem. The screen is often too narrow. There are too few words per line. This makes the email long and causes a lot of return sweeps (finding the next line).

Consider using landscape mode for reading emails. In other words, hold your phone horizontally. You’ll have fewer return sweeps (which is good) and fewer regressions (also good).

Most email apps do a good job of automatically resizing text to 10-20 words per line.

Here’s the same email from above in smartphone landscape mode:

3) Avoid full width on wide screens

If you have a wide monitor, avoid using the full screen for reading. Instead, resize your application to 1/2 or 1/3 of the screen width.

4) Use a vertical monitor

If you have a second monitor, put it in a vertical orientation (portrait mode). You can rotate the screen vertically on most monitor stands. This is the ultimate productivity hack for reading emails and documents.

Thanks for reading.

See you next week,

Nabeel