July 2005, Vol. 7 Issue 2
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Usability News is a free web newsletter that is produced by the Software Usability Research
Laboratory (SURL) at Wichita State University.
The SURL team specializes in software/website user
interface design, usability testing, and research in human-computer interaction.
Barbara S. Chaparro
The Effects of Line Length on Reading Online News
By A. Dawn Shaikh
Summary: This study examined the effects of line length on reading
speed, comprehension, and user satisfaction of online news articles. Twenty
college-age students read news articles displayed in 35, 55, 75, or 95
characters per line (cpl) from a computer monitor. Results showed that
passages formatted with 95 cpl resulted in faster reading speed. No effects
of line length were found for comprehension or satisfaction, however, users
indicated a strong preference for either the short or long line lengths.
The amount of text-based information available online is steadily increasing. Universities are
offering more online classes; publishers are releasing more online books and journals; and
consumers are gathering online news, weather, and product information daily. Therefore, the
examination of the factors that influence the
readability of online text is very important. In a recent
survey, Shaikh and Chaparro (2004) evaluated the reading habits of Internet users across five
document types (journal articles, news, newsletters, literature, and product information) and found
that users preferred to read journal articles in printed form, but other documents such as online
news, newsletters, and product reviews in online formats.
Research has shown that many aspects of physical layout of online text impact reading
performance and satisfaction; Dyson (2004) gives an excellent review. One such factor that has
been studied is line length, or the number of characters presented per line of text. Research
investigating line length for online text has been inconclusive. Several studies found that longer
line lengths (80 – 100 cpl) were read faster than short line lengths (Duchnicky and Kolers, 1983;
Dyson and Kipping, 1998). Contrary to these findings, other research suggests the use of shorter
line lengths. Dyson and Haselgrove (2001) found that 55 characters per line were read faster than
either 100 cpl or 25 cpl conditions. Similarly, a line length of 45-60 characters was recommended
by Grabinger and Osman-Jouchoux (1996) based on user preferences. Bernard, Fernandez, Hull,
and Chaparro (2003) found that adults preferred medium line length (76 cpl) and children
preferred shorter line lengths (45 cpl) when compared to 132 characters per line.
Shaikh and Chaparro (2004) found that 62% of respondents preferred to read news onscreen
rather than on paper. The goal of this study was to investigate the effects of line length on reading
Page 1 of 4Usability News 72 - Shaikh
performance of online news articles. This study investigated the
effects of four line len
ths (35, 55,
75, and 95 cpl) on reading speed, comprehension, and satisfaction.
Twenty college students from a Midwestern university volunteered to participate in the experiment
and were compensated with $25. All participants had 20/40 or better unaided or corrected vision.
Participants reported visiting websites daily, had experience reading
online, and were re
of the Internet.
News articles with approximately 375 words (M = 367.9) were selected from MSN®; and Yahoo®;
news. Average reading level for each passage was at the 12.0 grade level. The news articles
covered a variety of topics ranging from computer
viruses to innovative automobiles. The passa
used Arial 10-point font with 12-point interlinear spacing between lines. Each paragraph was
separated with an additional line break as is typically done on web pages. Hyphenation was not
used in the text.
A total of 19 comprehension questions were written for each article including one title, main idea,
and structure question and three factual and incidental questions, and 10 recognition questions
(see Dyson & Haselgrove, 2001). A background questionnaire was used to collect demographic
information as well as computer and Internet usage patterns. A Reading Satisfaction Evaluation
consisting of 11 questions on a 7-point Likert Scale collected user reactions to the passage layout,
perceived eyestrain, and fatigue. A Post-Experiment Questionnaire was used to determine layout
Following the completion of the consent form and the background questionnaire, participants were
seated approximately 52 cm from the screen. The pages of text were displayed using Internet
Explorer 6.0 in full screen mode to reduce distractions of tool bars, scroll bars, and menu items;
paging (with no scrolling) was used to navigate the passages. The HTML pages contained "Next"
and "Previous" buttons that users clicked with the mouse to navigate. All HTML pages were
accessed from the computer hard drive to minimize download time.
Participants read a total of eight short news articles presented in counterbalanced order for line
length. Two news articles were presented in each line length. Participants completed the set of
comprehension questions after reading each passage. The Reading Satisfaction Questionnaire was
given after each set of short passages. Following the last passage, the Post-Experiment
Questionnaire was administered.
Reading Speed. Reading time was converted to words per minute. Results from a one-way within
subjects ANOVA showed that there was a significant main effect of line length on reading speed, F
(3, 57) = 3.45, p = .02, η² = .15. The 95 cpl (M = 178.82, SD = 41.83) articles were read
significantly faster than any of the other line lengths (35 cpl M = 167.21, SD = 33.66; 55 cpl M =
167.38, SD = 33.96 ; 75 cpl M = 169.44, SD = 33.48) (Figure 1).
Page 2 of 4Usability News 72 - Shaikh
Figure 1. The effect of line length on reading speed.
Reading Efficiency. Reading efficiency was computed by multiplying the reading speed by the
percent correct on the comprehension questions. Results of a one-way within subjects ANOVA
showed a marginally significant effect of line length, F(3, 57) = 2.68, p = .06, η² = .12. Si
differences were found between 35 cpl and 95 cpl with the 95 cpl being more efficient.
Overall Comprehension. To compute an overall comprehension score, raw scores were adjusted
per question type to yield a total comprehension score of 6 (based on the six types of questions).
In doing this adjustment, each type of question was worth a total of one point. Results from a one-
way within subjects ANOVA showed no effect of line length on overall comprehension.
Comprehension by Question Type. Results from a one-way within subjects ANOVA revealed a
significant main effect of question type on comprehension, adjusted F(3.98, 75.69) = 10.193, p
= .001, η² = .35. Participants scored significantly lower on the structure questions than title, main
idea, and factual questions across all line lengths (Figure 2).
Figure 2. The effect of question type on comprehension.
Satisfaction & Preference. There was no main effect of line length on overall satisfaction. There
were also no significant differences in preference. However,
60% of participants chose either 35 cpl
(30%) or 95 cpl (30%) as the most preferred line length. On the other hand, 100% of participants
chose either 35 cpl (45%) or 95 cpl (55%) as the least preferred line length.
Page 3 of 4Usability News 72 - Shaikh
This study examined the effects of line length on reading performance. Reading rates were found
to be fastest at 95 cpl. Readers reported either liking or disliking the extreme line lengths (35 cpl,
95 cpl). Those that liked the 35 cpl indicated that the short line length facilitated "faster" reading
and was easier because it required less eye movement. Those
that liked the 95 cpl stated that they
liked having more information on a page at one time. Although some participants reported that
they felt like they were reading faster at 35 cpl, this condition actually resulted in the slowest
Circulation of newspapers at 814 of America’s largest daily newspapers declined 1.9% from
September 2004 to March 2005 (Shin, 2005). This decline is part of a 20-year trend in newspaper
circulation and is due, in part, to the increased use of the Internet and other forms of media (cable,
satellite, etc). As users continue to choose online news sources, it is imperative to understand
factors that contribute to improving the overall online reading experience for news. Participants
were able to read news articles significantly faster while maintaining high reading efficiency using
95 cpl. Despite the fact that there were no differences in satisfaction scores, a line length that
supports faster reading could impact the overall experience for users of online news sources.
Note: For additional information on this study, please see the proceedings of the Human Factors
and Ergonomics Society's 49th (2004) Annual Meeting, Orlando, FL.
Bernard, M. L., Fernandez, M., Hull, S., & Chaparro, B. S. (2003). The effects of line length on
children's and adults' perceived and actual online reading performance. Proceedings of the Human
Factors and Ergonomics Society 47th Annual Meeting, 1375-1379.
Duchnicky, R. L., & Kolers, P. A. (1983). Readability of text scrolled on visual display terminals as a
function of window size. Human Factors, 25, 683-692.
Dyson, M. C. (2004). How physical text layout affects reading from screen. Behaviour and
Information Technology, 23, 377-393.
Dyson, M. C., & Haselgrove, M. (2001). The influence of reading speed and line length on the
effectiveness of reading from screen. International Journal of Human-Computer Studies, 54, 585-
Dyson, M. C., & Kipping, G. J. (1998). The effects of line length and method of movement on
patterns of reading from screen. Visible Language, 32, 150-181.
Grabinger, R. S., & Osman-Jouchoux, R. (1996). Designing screens for learning. In H. van
Oostendorp & S. de Mul (Eds.), Cognitive aspects of electronic text processing. Norwood, NJ: Ablex
Shaikh, A. D., & Chaparro, B. S. (2004). A survey of online reading habits of Internet users.
Proceedings of the Human Factors and Ergonomics Society 48th Annual Meeting, 875-879.
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