Reading Skills Transfer Best from Home Language to a Second Language: Policy Lessons from Two Field Experiments in South Africa

Abstract

In many countries, children need to become proficient in both their home language (L1) and an international language, such as English (L2). Governments face tradeoffs in how to prioritize these two objectives. We provide empirical evidence on cross-linguistic transfer between L1 and L2, using the results of two randomized evaluations of Structured Pedagogy Programs implemented in South Africa. The programs had the same design, implementing organization, and duration. The key difference is that one program targeted the teaching of reading in L1, while the other targeted L2. We find that both interventions had positive effects on the languages they targeted. The L1 intervention also had a positive effect on L2 reading proficiency. In contrast, the L2 intervention had a negative effect on L1 outcomes, for the lower-performing students. These results are consistent with the Simple View of Reading and suggest that decoding skills are best learned in L1. It is thus cost-effective to prioritize learning to read in L1, as well as supporting teachers in this subject, even if becoming proficient in L2 is also regarded as an important policy objective.

Keywords:

• Language transfer
• mother-tongue
• language policy
• teacher professional development
• structured pedagogy

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No potential conflict of interest was reported by the author(s).

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The data and code underlying the results reported in this manuscript are openly available in Harvard Dataverse: https://doi.org/10.7910/DVN/RSUADW.

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Notes

1 Low-cost private schools in India, for example, often use English as the language of instruction. https://www.epw.in/journal/2021/13/special-articles/learning-and-language.html. Accessed June 6th 2022.

2 Early grade language of instruction (LOI) in Botswana is either Setswana or English, even though 26 languages are spoken in the country. Kiswahili is the early-grade LOI in Tanzania, and urban centers in Kenya. English is the LOI in urban Uganda. In rural areas the language of the catchment area is used, which is typically the mother tongue.

3 https://www.worldpoliticsreview.com/in-rwanda-language-change-in-schools-leaves-students-and-teachers-struggling/. Accessed October 10th 2022. https://www.washingtonpost.com/politics/2020/01/24/third-time-11-years-rwanda-changed-language-used-primary-schools/. Accessed May 9th 2023.

4 The majority of schools in South Africa are public (93%) (Department of Basic Education, 2021). Public schools in South Africa are classified by school Socio-Economic Status, referred to as quintiles. These are not perfectly proportional; quintile 1 to 3 schools are the poorest constituting 83% of schools overall. Furthermore, quintile 1 to 3 schools are non-fee paying.

5 Class Act educational services and Molteno Institute for Language and Literacy.

6 Neither program had any specific components aimed at transferring literacy skills across languages.

7 Note that since the curriculum stipulates that teachers should dedicate 7–8 h to teaching home language, compared to 3–4 h teaching EFAL. The different amount of time allocated to the targeted language of the two interventions may have contributed both the main outcomes and transfer.

8 The studies also included additional treatment arms, to compare the cost-effectiveness of different modalities of implementation. We restrict this paper to the treatment arms that are comparable across studies, and were also the most cost-effective.

9 Eight additional words were added in the word recognition test for EGRS II. We drop these items for our analysis. The same story was used for Oral Reading Comprehension although the time to administer the task changed from 1 to 3 min. We adjust for this and use only 1 min reading across both studies. Any other differences in the test administration are also addressed for the analysis.

10 The control variables include the different baseline measures of student home language literacy (phonemic awareness, letter recognition, etc.), student gender and age, and some measures of school socio-economic status.

11 The strongest assumption is that $M_{\mathit{icsb}}$ is independent of $y_{\mathit{icsb}},$ conditional on treatment and baseline covariates, $X_{\mathit{icsb}}^{\prime }.$ Even though treatment is random, there might be other factors that cause both M and y.

12 The outcomes reported in Figure 2 aggregate scores constructed using principal component analysis, and standardized to have a control mean of one and standard deviation of zero. See Table 2 for the constituent indicators for the literacy scores. There were no floor effects in home language literacy, but there were floor effects in English reading proficiency.

13 Note that there is no effect, positive or negative, for the bottom quintile of students because of floor effects: in both the treatment and control arms, the bottom fifth of students cannot read a single word in their home language.

14 In South Africa one teacher teachers all the subjects at early grade. So, the same grade 1 teacher teaches Home Language, English and Mathematics.

15 As discussed above, the L1 curriculum places a large emphasis on mastering decoding in grade 1, the L2 curriculum emphasises oral vocabulary. The assumption is that students already have a basic command of the oral vocabulary in their L1, and that the decoding skills they learn in L1 will transfer to L2.