| { | |
| "original_study": { | |
| "claim": { | |
| "hypothesis": "Bilingual students, on average, achieve higher scores in English as a foreign language than their monolingual classmates, once individual and family background characteristics are taken into account.", | |
| "hypothesis_location": "Section 1.4 Research questions, Hypothesis 1a.", | |
| "statement": "After adjusting for general cognitive abilities, age, gender, socio-economic status, parental education, and cultural capital, membership in the bilingual group is positively related to English foreign language achievement: bilingual students score about 2.68 points higher than monolinguals on the English scale, and this effect is statistically significant.", | |
| "statement_location": "Results section 3.2, Table 3 ('Multiple regression models explaining English achievement of bilinguals'), Model B.", | |
| "study_type": "Observational" | |
| }, | |
| "data": { | |
| "source": "Secondary analysis of the ELEMENT study (Assessment of Reading and Mathematics Development Study), a large-scale assessment conducted in public elementary schools in a major German city.", | |
| "wave_or_subset": "Sixth-grade of the ELEMENT cohort.", | |
| "sample_size": "2,835 students nested in 134 elementary school classes.", | |
| "unit_of_analysis": "Individual student.", | |
| "access_details": "not stated", | |
| "notes": "Students attend public elementary schools; the sample is representative for sixth-grade students in the city. Language-group classification is based on parent (and, if missing, student) reports of languages spoken regularly at home. The analytic sample includes a monolingual German group (n = 1,896) and several bilingual groups (Arabic–German, Chinese–German, Polish–German, Turkish–German, and a heterogeneous ‘other bilingual’ group). Missing data were handled via multiple imputation (five imputed datasets), and analyses accounted for the clustering of students within classes using complex survey procedures in Mplus 5.21." | |
| }, | |
| "method": { | |
| "description": "The authors used multiple regression models on a large, imputed sixth-grade dataset to test whether being bilingual (speaking a minority language at home plus German) is associated with higher English foreign language achievement compared to monolingual German students, controlling for cognitive and socio-cultural background variables.", | |
| "steps": [ | |
| "Use ELEMENT study data to identify students’ home language(s) from parent reports (and student reports when parent data are missing), and classify students as monolingual German or bilingual (speaking German and another language regularly at home).", | |
| "Measure English foreign language achievement in grade 6 with a Cloze test consisting of four texts and 91 word-completion items, scaled using one-parameter item response theory; obtain individual weighted likelihood estimates (WLEs).", | |
| "Collect background covariates: general cognitive abilities (from the CFT4-12R verbal and figural analogies subtests in grade 4), age, gender, socio-economic status (HISEI), parental education, and cultural capital (number of books at home).", | |
| "Handle missing data using multiple imputation (five imputed datasets) based on a background model including individual and classroom-level factors; combine results across imputations.", | |
| "Estimate an uncontrolled regression model of English achievement on a binary indicator for bilingual-group membership (Model A).", | |
| "Estimate a controlled multiple regression model of English achievement on bilingual-group membership, adding general cognitive abilities, age, gender, socio-economic status, parental education, and cultural capital as covariates (Model B).", | |
| "Account for the nested data structure (students within classes) by using complex survey options in Mplus 5.21 when fitting the regression models." | |
| ], | |
| "models": "Multiple linear regression models predicting English foreign language achievement from bilingual-group membership and background covariates.", | |
| "outcome_variable": "English language achievement in grade 6.", | |
| "independent_variables": "Binary indicator for group membership (1 = bilingual student who speaks a minority language at home and German; 0 = monolingual German student).", | |
| "control_variables": "General cognitive abilities (CFT4-12R composite), age (centered), gender (girls = 1), socio-economic status (HISEI, z-score), parental education (highest parental qualification, z-score), and cultural capital (number of books at home, z-score).", | |
| "tools_software": "Mplus 5.21" | |
| }, | |
| "results": { | |
| "summary": "In the uncontrolled model, bilingual students score lower in English than monolinguals. However, once general cognitive abilities, age, gender, socio-economic status, parental education, and cultural capital are held constant, the sign reverses: bilingual-group membership is positively and significantly associated with English foreign language achievement, indicating a small advantage for bilinguals over monolinguals.", | |
| "numerical_results": [ | |
| { | |
| "outcome_name": "English foreign language achievement (Cloze test WLE score)", | |
| "value": 2.68, | |
| "unit": "score points on the English achievement scale (M = 100, SD = 20)", | |
| "effect_size": "unstandardized multiple regression coefficient for bilingual-group membership in Model B of Table 3", | |
| "confidence_interval": { | |
| "lower": "not stated", | |
| "upper": "not stated", | |
| "level": "not stated" | |
| }, | |
| "p_value": "< .01", | |
| "statistical_significance": 1, | |
| "direction": "positive" | |
| } | |
| ] | |
| }, | |
| "metadata": { | |
| "original_paper_id": "10.1016/j.learninstruc.2014.12.001", | |
| "original_paper_title": "The effect of speaking a minority language at home on foreign language learning", | |
| "original_paper_code": "not stated", | |
| "original_paper_data": "not stated" | |
| } | |
| } | |
| } | |