Introduction

Reading proficiency is the foundation of learning; yet, just over one-third of the United States population reads at a proficient level, according to the US Department of Education. This unfortunate trend begins early when children are learning to read. If students are not strong readers by the 4th grade, they are not likely to read well in the 8th, 12th, and beyond.

Personalized reading formats offer an opportunity to shift this trend and serve as a valuable complement to quality instruction.

A 2015 study aimed to determine the range of student readers who would benefit from personalized reading formats, also known as “Tuned Text.” Almost all students improved their reading performance by using a text format different from their standard reading textbook format. Not only struggling readers but also those already performing above grade level experienced proficiency gains measured by changes in reading fluency.

To make personalized text format adjustments for each student in a classroom at scale, technology-enabled solutions are required.

In 2018, the research team partnered with Adobe to conduct a tech proof-of-concept classroom test using a prototype build of Acrobat Reader. New features in the prototype included functionality to adjust key readability features. Although small in scale, it provided evidence that digital delivery could be both effective and scalable.

This white paper summarizes the findings from the digital proof-of-concept study.

Background
Tune Your Text: The Role of Readability Features

Reading fluency is the ability to read quickly, accurately, and with proper expression. Fluency is measured as words correct per minute (WCPM). Fluent readers also read in phrases and add intonation appropriately, a sign that they understand what they are reading (Hasbrouck, 2006).

Fluency is the bridge to comprehension. Improved fluency allows readers to devote more attention to meaning rather than decoding, increasing their learning capacity.

When children or adults read with their best text format, reading fluency immediately improves. This is an instantaneous change in reading performance, not the result of a long-term intervention or reading program (similar to putting on eyeglasses, the correct adjustment produces an immediate improvement).

The technology available today can help readers maximize their potential to comprehend quickly and accurately. Reading applications should allow users to control Readability Features, including font, character shape, size, character width, and character and line spacing.

2015 Breakthrough Study Results

In 2015, a classroom study investigated whether text format adjustments could improve fluency for readers across all reading levels. Using Microsoft Word, the researchers varied five sections of a reading passage by adjusting font, text size, character spacing, and character width. The third-grade students read aloud, and their fluency was scored.

Ninety-five percent of students improved using at least one of the modified formats. The class gained an average of 28% words correct per minute (WCPM). Several students who were already reading above grade level had above-average gains, demonstrating that personalized reading formats can benefit a wide range of readers. No single format proved most effective for all readers.

The findings highlight that both strong and struggling readers can benefit, and that no one text format is best for all readers.

For more details, see the white paper, “Classroom Evidence: Typography Impacts Reading Fluency for Strong and Struggling Readers.”

2018 Digital Delivery Proof of Concept Study with Adobe

In 2018, the RevReading project team approached Adobe to discuss the benefits of using technology to deliver personalized reading formats at scale. Adobe agreed to add functionality to a prototype version of Adobe Acrobat Reader for use in classroom testing.

Methods

Participants

Two classrooms from a private school in South San Jose participated: one third-grade and one seventh-grade class. Both groups were above-average readers, with national benchmark scores averaging in the 74th percentile for third grade and the 75th percentile for seventh grade. Parental consent was required for participation.

Adobe Reader Prototype

Adobe developed a prototype version of Acrobat Reader for iPad that incorporated readability features, including controls for font, size, line spacing, character spacing, and character width (“stretch”). This prototype was used to deliver the study materials in multiple text formats.

Reading Passages

Students read grade-level appropriate passages: Mission (Lexile 810–1000) for third grade and Frederick Douglass (Lexile 1010–1200) for seventh grade. Each passage was divided into five contiguous sections, which were read in order. Lexile measures were confirmed through Lexile.com to ensure that the texts reflected grade-level complexity and were consistent across sections.

Text Formats Tested

Five text formats were included in the study. Times New Roman served as the control condition. The remaining four formats were based on Avenir, a clean, round font, with adjustments to size, character spacing, and character width.

Using Adobe’s prototype on iPads, the researchers modified the settings from the defaults to generate each of the text formats in the study. See charts and text format samples below.

Grade 3 Test Formats

 

Grade 7 Test Formats

Procedure

Students read aloud each story in order, with each section presented in a different format. The assignment of formats to sections was counterbalanced to eliminate any potential order effects. Each section was read for two minutes. A tester conducted the session while an observer documented both timing and qualitative details, including whether students sat still or showed signs of engagement. Observers also recorded responses to simple prompts, such as “Do you like to read for pleasure?” All readings were audio-recorded and later scored for oral reading fluency using Running Record methods (Clay, 2000; Fountas & Pinnell, 2017).

Results

Grade 3

Only 12% of the third-grade students read best with the control font, Times New Roman. A clean, round font (Avenir in this study) was sufficient to improve fluency for 48% of the students. Adding character spacing and character width expansion to Avenir helped 39% of the students.

When reading with a better format, 88% of students experienced immediate fluency gains, with an average increase of 17% in words correct per minute (WCPM).

Risk Reduction: Teachers use the Hasbrouck-Tindal Oral Reading Fluency benchmarks (Hasbrouck & Tindal, 2005) to assess the reading progress of their students. The average expected improvement in oral reading fluency during 3^rd grade is about 36 words correct per minute (WCPM). In this test, students demonstrated an average improvement of 23 WCPM, which represents a substantial portion of the expected annual growth. One student increased 43 WCPM, exceeding that benchmark.

Readers of All Levels Benefit: The study demonstrated benefits across readers of all reading levels. Coincidentally, the slowest and fastest readers in the class gained 27 words correct per minute. Text formats that better meet each reader’s needs benefit not only struggling readers but also those already reading at a high level.

Student Highlights, 3rd Grade:

Grade 7

While still prevalent, using oral reading tests to assess reading fluency becomes more challenging as children get older. Students recognize the need to add expression, which slows reading rate. For faster readers, the ability to articulate quickly becomes a limiting factor.

In the 7th-grade study, 25% of the students read best with the control font, Times New Roman. The option to read with a clean, round font (Avenir in this study) maximized the reading fluency of 22% of the students. Additional character spacing and character expansion improved the reading proficiency of 53% of the students.

When the reading was presented in a better format, student performance improved immediately: 75% of students experienced immediate gains in reading fluency, with an average increase of 8%. Even small gains are meaningful, given the already high baseline fluency of these students.

Risk Reduction: The Hasbrouck-Tindal (Hasbrouck & Tindal, 2005) average expected oral reading fluency improvement during 7^th grade is about 22 WCPM. The 7th-grade students demonstrated an average improvement of 15 WCPM, delivering 68% of that expected annual growth. One student increased 30 WCPM, exceeding that benchmark.

Student Highlights, 7th Grade:

Individual outcomes from the 7th-grade classes illustrate the continuing impact of personalized formats on this age group. Both average and top-performing readers demonstrated measurable gains in reading performance.

Results Summary

Across both grade levels, most students experienced immediate fluency gains when reading in an alternate text format. Improvements were observed among struggling readers and those already performing at high levels, underscoring that personalization can benefit all students. These results validate earlier evidence; Adobe’s enhanced Reader prototype demonstrates the possibility of using digital delivery to allow reader customization and provide measurable improvements in fluency.

Conclusion

The 2015 and 2018 research studies demonstrated that small changes to text format produce immediate gains in oral reading fluency. In the 2018 technology proof of concept, conducted with third- and seventh-grade students, most readers improved their reading fluency within a single session, including some who were reading above grade level. Different or finer adjustments may support even greater reading proficiency gains.

Digital personalization is feasible, offering the potential for scaled solutions. The challenges ahead are (1) developing assessment tools that can quickly and accurately identify each individual’s best reading format and store it in a user profile, and (2) ensuring that technology companies offer personalization on their platforms.

Implications: Change the Student’s Trajectory

Our research has consistently shown that small changes to text format have an immediate impact on reading fluency. In summary,

• There is no best format for all readers; personalization is required
• Children and adults benefit from the use of Readability Features
• Performance improvements occurred across all levels of readers
• Reading proficiency gains are immediate

A student’s relative reading trajectory is generally established by 4^th grade. The use of personalized reading formats creates the opportunity to shift that trajectory, adding capacity for learning. Additionally, reading ability influences confidence and self-esteem, shapes friendships, determines educational and career paths, income, and life experiences.

Next Steps: Immediate Action

Let’s start thinking about reading differently. Making it easier for children to acquire reading skills puts them on the path of lifelong learning. Increasing reading performance in adults produces more life and career opportunities.

To create opportunities for large-scale implementation, assessment tools that identify and save each reader’s best format, and technology platforms that offer personalization are required. Several tech and edtech companies are incorporating readability features today. The Readability community of education and research partners is working to ensure research-informed solutions.

Together, we can deliver better readability to children and adults who seek knowledge, learn in school, track trends, and enjoy reading.

 

Acknowledgments

We thank Mike Dillon of Adobe for his early support and Rick Treitman of Adobe for his sustained commitment to advancing Adobe’s readability initiative. We also acknowledge the broader Adobe team for their partnership in developing, testing, and implementing readability Reading Settings in Acrobat Reader for the mobile platform.

The principals of the RevReading Project are recognized for their contributions to this work. Appreciation is extended to the participating students and their families, as well as the teachers and school administrators whose support made this research possible.

 

2025 Editor’s Note

This 2018 study is republished with minor updates, including Adobe’s role, which was not disclosed in the original 2019 version. Adobe’s role was announced at Adobe MAX in 2020. See the article on Rick Treitman’s presentation.

 

 

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