Leaders of this midsized, mid-Atlantic district were perplexed. The district—which requested anonymity for this story—had recently invested heavily in early-childhood education.
It expanded universal free preschool for 3- and 4-year-olds, scheduled daily two-hour literacy blocks in the early grades—divided among phonics, comprehension, and needs-based small-group instruction—and provided common, coordinated planning time for teachers.
Despite these efforts, the district continued to see wide disparities in literacy assessment among K-2 students—not just between schools but from classroom to classroom.
To understand why students’ scores hadn’t improved uniformly, the district partnered with the nonprofit SERP Institute (Strategic Education Research Partnership). Close observations of classroom literacy blocks revealed two key findings. First, how teachers allocate instructional time during literacy blocks matters—in unexpected ways. Secondly, students performed better on standardized assessments when teachers routinely taught new vocabulary and encouraged more than one-word responses during comprehension lessons.
“I do think the messaging around the science of reading has been interpreted on the ground sometimes as: Do phonics, only do phonics. Don’t worry about anything else,” said Margaret Troyer, the director of literacy research and development at SERP. “And if the goal is to build lifelong readers, we have to show them that there’s something they can get out of reading a book other than just finding what sounds the letters make.”
Practicing oral language during comprehension matters
Troyer and Wafaa Ahmed, an assistant project director at SERP, spent more than 80 hours during the 2021-22 school year observing literacy blocks in 42 K-2 classrooms across six of the district’s schools. The district’s model called for literacy time to be divided into 25% on phonics, 25% on whole-class comprehension instruction, and 50% on small-group instruction.
In practice, time allocation varied widely. Teachers spent anywhere from 7% to 42% of the literacy block on comprehension and between 10% to 56% on whole-class phonics instruction. Some teachers devoted nearly twice as much time to comprehension as phonics, while others did the reverse.
“Certainly, there are teachers who are letting the other pieces of the literacy block crowd out the comprehension instruction,” Troyer said.
That doesn’t bode well for students, according to the researchers. More time spent on phonics was associated with lower DIBELS scores, whereas more time spent on comprehension was linked with higher scores on the standardized tests designed to evaluate literacy skills in K-8 students.
Findings echo research on phonics limits
The SERP study, currently under peer review, adds to a growing body of research suggesting limits to phonics instruction.
A 2024 study from Texas A&M University found that while phonics is essential for early reading development, its benefits plateau once students master foundational skills.
Researchers reviewed 16 studies involving students in grades P-1 and found that up to 10.2 hours of phonemic-awareness instruction improved students’ skills. Beyond that, additional instruction showed diminishing returns.
“Phonemic-awareness instruction is just one of the steps that will bring us to kids starting to read and spell. … After a while, you wouldn’t expect a typical child to go on forever and ever needing this,” Florina Erbeli, an assistant professor of educational psychology at Texas A&M and the lead author of that research, told EdWeek.
What happens during comprehension lessons matters
In the SERP study, the instructional practices most strongly associated with higher DIBELS scores occurred almost entirely during comprehension lessons, Troyer said. These included defining vocabulary during read-alouds and encouraging students to expand their answers beyond one-word responses.
Although most teachers asked questions during read-alouds, the vast majority of these exchanges were “closed-ended”: A teacher asked a question, a student gave a brief answer, and the teacher would move on. Rarer were exchanges in which the teacher continued the dialogue, Troyer said.
Other researchers emphasize the importance of these extended interactions between teachers and young learners. Sonia Cabell, a professor at the Florida Center for Reading Research, says teachers can improve the oral-language skills of learners, starting as early as preschool, by engaging in “meaningful one-on-one conversations with students throughout the school day.”
“The benefits of going back-and-forth... are well-documented in the literature,” Cabell said. “The idea is that you’re building on what students say and then providing them with another opportunity to be an active participant in the conversation.”
Teachers value comprehension, but time is tight
Read-alouds offer a natural opportunity to build comprehension, vocabulary, and discussion. Teachers widely recognize their importance. In a 2019 study asking 1st through 4th grade teachers about read-alouds, all respondents said the practice was important, with more than half calling them indispensable.
But teachers don’t always get around to them.
“Teachers are being asked to do a lot,” Troyer said. “As for the teachers who weren’t making the time to read aloud to students, that’s not OK for those kids. But they’re not finding the time to read aloud to students because they’re trying to do all the other things that they’re being asked to do.”
Troyer acknowledges the pressures teachers are under but also advises them: “Don’t let phonics instruction squeeze out time for comprehensive instruction.”
