Much of the conversation on the science of reading has been focused on how to help students in grades K-3 learn how to read. However, one question that I see consistently come up is how do we help students who are learning English as another language. Unfortunately, most of the major studies on the science of reading, did not specifically look at this issue. I decided to dig deeper into the research on this topic, by looking at what the meta-analyses show. I searched on the Education Source data-base for every meta-analysis on the topic. In total, I was able to find 15 meta-analyses dating back to 2004. 

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It is important to look at education science via meta-analysis, because they combine all of the studies on a given topic, to find the mean result. This is crucial in education, because we see a large amount of variability in education studies and meta-analysis helps to correct for this problem. That said, it is important to remember that a meta-analysis is only as valid as the studies in it, and the inclusion criteria was quite weak for many of these studies. Indeed, only 3 of these meta-analyses excluded studies without control groups. Meaning, that many low quality studies were included. This lack of high quality studies, might be less reflective of the meta-analysis authors having low standards, but rather a lack of available research for them to pull studies from. As ELL instruction is a niche topic, there are less total studies.  This all said, I think the best practice is to base our understanding of the science, based on the available research, knowing that we may have to update that understanding as more high quality research is conducted.  

All but one of these meta-analyses was looking at how best to support a specific literacy skill, for ELL students. So to make things easier, I have organized the findings of these 15 meta-analyses according to each researched literacy skill. 

Oral:

In 2021, Jia et al. conducted a meta-analysis of 13 studies that examined the impact of decoding instruction on listening outcomes. The inclusion criterion for this study was weak, which could lead to inflated effect sizes. Nonetheless, the authors found a mean Hedge’s g effect size of .55, CI= [.34, .75], with the strongest results observed for elementary-aged students (g= .87 CI= [.46, 1.28].).

Decoding instruction refers to the process of teaching students how to break down written words into their individual sounds, which is crucial for developing reading skills. This meta-analysis suggests that decoding instruction can also improve listening outcomes, which could have important implications for language learners. However, the weak inclusion criteria used in this study mean that the results should be interpreted with caution.

In the same year, TESOL conducted a meta-analysis of 17 studies that investigated the factors that influence pronunciation instruction. Like the previous study, the inclusion criteria for this meta-analysis were weak, which raises questions about the reliability of the findings. Despite this limitation, the authors found a mean Cohen’s d effect size of .61CI= [.47, .74]. p=.001 for the explicit instruction of pronunciation. This suggests that explicit instruction can be effective for improving pronunciation accuracy in language learners.

The authors also noted that teachers should focus on improving segmental accuracy at the phoneme level, which is the primary correlate of accentedness. However, they also cautioned that becoming native-like in pronunciation is rare for adult  learners. This highlights the importance of realistic goals and expectations when it comes to pronunciation instruction.

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Finally, in 2014, Roessingh et al. conducted a literature review of 12 studies on effective ESL programs in high school. The authors identified several effective pedagogies, including ESL buddies, collaboration, thematic organization, and high-level questions. However, the reliability of these findings is limited by the fact that the inclusion criteria and descriptive statistics were not reported.

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In conclusion, these three studies provide some insights into the effectiveness of different instructional approaches for language learners. However, the limitations of weak inclusion criteria and incomplete reporting of statistics highlight the importance of rigorously designed and reported studies in this area. Future research should strive to address these limitations to provide more reliable evidence on the effectiveness of different instructional approaches.

Grammar:

Language learners face many challenges, including mastering complex grammatical structures. In 2005, Goldschneider et al. conducted a study that examined error rates for different morphemes and found that students need instruction on several types, including ing, plural, possessive, regular, past tense, third person singular, and articles. This highlights the importance of targeted instruction to address specific grammatical challenges faced by language learners.

In 2020, Schenck et al. conducted a meta-analysis of 15 studies on grammar feedback. While the inclusion criteria for this study were weak, the results suggest that several strategies can be effective for providing grammar feedback to language learners. The authors found that meta-linguistic feedback (written) had the largest effect size g= 1.99, followed by direct feedback g=1.54.