Kindle Review – Kindle Fire Review, Kindle 4 Review

There’s an interesting discussion at the official kindle forum comparing the amount of text displayed per page on the Kindle 2 and the Kindle DX. It also looks at words per page for different font sizes. 

It got me thinking about the whole concept of page size and reading. Each of us have our personal preferences.

However are there any studies on what impact page size has on reading?

What about font size – What impact does that have on reading?

Summary of Findings about Font and Screen Size

Here are the main findings from research studies -

1. Reading speed increases with more words per screen. There are some studies that are undecided about this. 
2. Reading speed increases with size of the screen. There are some studies that claim this doesn’t happen. 
3. Size of characters is only important for legibility. After characters are legible, their size doesn’t seem to impact reading speed.
4. Older readers prefer font size 14 over size 12. Only two sizes were compared.
5. Children below 7 prefer font size 24 and those aged 7 or 8 prefer font size 18.
6. Dyslexic students need a critical font size to be able to reach their highest reading speed and this is higher than that for non-dyslexic students.
7. Black characters on a white background produce the best readability.
8. Paging is better than scrolling.
9. Increasing the Spacing between lines improves clarity.
10. Serif fonts (Times New Roman, little arches/serifs on the characters) are better than sans serif (Arial, Verdana) for print on paper. The results are supposed to be the reverse for computer screens.

Most of the research is not very extensive, some is hidden behind paywalls, and there are still a lot of unknowns.

Impact of Font Size and Screen size on reading

Words Per Screen

Reading speed tends to increase with increase in the number of words.

Paul Muter’s Article, Interface Design and Optimization of Reading of Continuous Text, says -

With respect to words per screen, Muter, Latremouille, Treurniet, and Beam (1982) suggested that reading speed tends to decrease as words per page decreases. Findings consistent with this idea have been reported several times (Creed, Dennis, & Newstead, 1988; de Bruijn, de Mul, & van Oostendorp, 1992; Reisel & Shneiderman, 1987).

Screen Size

Large screens are better for reading.

Again Paul Muter’s article -

There is both theory (Lansdale, 1988) and data (de Bruijn, de Mul, & van Oostendorp, 1992; Dillon, Richardson, & McKnight, 1990) to support the idea that large screens enhance the processing of text, perhaps partly because the number of words per screen can be larger (see above).

A slightly contradictory report from the University of Texas says that comprehension and performance rates are not significantly affected by size of the screen -

Taken together, these results indicate that while comprehension and performance rates may not be significantly affected by the variations in screen size used here, subjects clearly prefer a larger screen. Furthermore they manipulate the text more with a small window.

It was interesting that users complained about having to do frequent page turns when using smaller screen sizes and still no difference was found due to screen size – Perhaps it’s because there were no time limits. Perhaps given a 10 minute time limit you can read more and/or better with larger screens.

Size of Characters

This seems to have no impact on reading speed. Note that the impact on dyslexic readers is discussed later and this obviously assumes the text size is one people can actually read.

Again the Paul Muter article -

 Within reasonable limits, size of the characters has no effect on proofreading speed (Gould & Grischkowsky, 1986). The probable reason is analogous to the reason that distance has no effect (see above).

Distance:

Within reasonable limits, the distance between the reader and the reading material has no effect on perceptual span (Morrison & Rayner, 1981) or reading efficiency (Kruk & Muter, 1984). With increasing distance, retinal image size decreases linearly, but so does retinal eccentricity (distance of the image from the fovea), and these two effects offset each other exactly. Acuity is a decreasing linear function of eccentricity (Anstis, 1974).

The Web Style Guide says that readers like large type and generous space between lines (they use research done using print on paper) -

Readers like large type more than most designers do. It’s not just the taste for graphic subtlety that drives the dichotomy: web designers are usually under great pressure to “cram in as much as possible,” and smaller type means more words per inch.

Generous leading (line spacing) is a key to legibility. Larger type helps, but the data suggests that a moderate type size—11 points—and a standard 13 points of leading yields the best balance of type size and overall reading comfort.

Impact of Size of Characters on Reading by Older Adults

There’s a study by the Psychology Department at the University of Wichita that found that for readers aged 62 to 83 years there was a strong preference for font size 14 over font size 12.

Impact of Size of Characters on Reading in Children

A compilation of studies on reading by Cengage is really interesting -

Serif fonts aid struggling readers by making words easier to read. They also reduce eye fatigue.

Font Size 24 is much easier to read for children under seven and font size 18 for children aged 7 and 8. An 18 point font size was preferred by 66.7% of third graders.

More line spacing helps children track words better.

Most legible combination is black print on a white background.

Use of large print tests improves the performance of learning disabled children.

Print Sizes and Dyslexic Students

A study by Beth O’Brien, J. Stephen Masfield, and Gordon E. Legge on the effect of print size on reading speed of dyslexic students shows that there is a critical font size at which dyslexic students reach their maximum reading speed and that this critical size is larger than that for non-dyslexic students.

their critical print sizes were larger than those of the controls, indicating that they needed larger print to support maximum reading rates.

It’s interesting to think that the print size in textbooks is unsuited for at least 5% of students.

Impact of Various Factors on reading

A few interesting observations from the Paul Muter article for paper reading -

1. Black characters on a white background produce faster reading and most readers prefer it.
2. The effects of type size, line length, and interline spacing interact. 

The paper does point out that we can’t really extend these studies to computer screens – Can we extend them to eInk?

Scrolling vs Paging

Paging performed much better than scrolling -

Paging is apparently superior to scrolling in terms of both performance and user preference (Kolers, Duchnicky, & Ferguson, 1981; Schwarz, Beldie, & Pastoor, 1983).

One advantage of paging is that incidental memory for location within a page (Rothkopf, 1971) may facilitate processing.

Spacing between lines

Very interesting results for line spacing -

Evidence of Wilkins and Nimmo-Smith (1987) suggests that increasing spacing between lines and proportionately decreasing horizontal spacing between letters may improve the clarity and comfort of text without affecting the density of the text.

Close inter-line spacing may impair reading because of vertical masking, and because return sweeps are more difficult (Kruk & Muter, 1984).

Evidence of Lunn and Banks (1986) suggests that interline spacing should be variable to prevent fatigue resulting from adaptation to spatial frequency.

Looking at eReaders with this knowledge

Now that we have a good idea of what makes for a better reading experience it’s interesting to look at how eReaders stack up. It’s worth noting that most of the above studies were done for paper or electronic screens – ePaper is neither so while it’s likely that the same results apply it’s not guaranteed.

1. eReaders do really well in terms of letting users increase the font size, change the spacing between lines, and changing the number of words per line.
2. eReaders let every reader adjust any book to his exact preferences.
3. Having a larger screen helps – However, there is enough ambiguity in some of the survey results to indicate that the difference might not be much. 
4. Color introduces a lot of problems – It’s quite possible that reading will be tougher with color ePaper screens than with black and white eInk. Please read the P. Muter paper to see why this is.
5. eReaders really expand the reading population – low vision readers, dyslexic readers, and more can join in. Plus you have text to speech for blind readers.

A lot of eReader benefits are not well researched and not well-known. In fact, even reading on LCD screens is not well researched. We spend hours and hours every day reading on screens, on paper, and now on eReaders – Yet we haven’t spent much time or effort to measure the quality of reading or to improve it. 

eReaders are a big step forward – However, we need solid research to back them up. Hopefully, the next time the NY Times writes an unresearched, biased ’LCDs are just as good for reading as eInk’ article there are proven studies to show which one is better, why, and by how much.

I’ll leave you with this quote from Paul Muter’s excellent paper -

“Reading is the means by which the world does a large part of its work….

The slightest improvement either in the page or in the method of reading means a great service to the human race”

(Huey, 1908).

Filed under: evolution Tagged: | future of reading, kindle font size