| { | |
| "original_study": { | |
| "claim": { | |
| "hypothesis": "Bilingual group membership will be positively associated with foreign language achievement when controlling for background variables.", | |
| "hypothesis_location": "the hypothesis is stated in the 1.4. Research questions section; it is also discussed in the abstract, introduction, section 1.2. Factors affecting language learning.", | |
| "statement": "Controlling for cognitive abilities, age, gender, socio-economic status, parental education, and indicators of cultural capital, the analysis revealed a general positive trend between bilingualism and English foreign language achievement (estimate = 2.68; p < .01).", | |
| "statement_location": "Table 3, Model B (Bilingual=1)", | |
| "study_type": "Observational" | |
| }, | |
| "data": { | |
| "source": "the main source: Assessment of Reading and Mathematics Development Study (ELEMENT); for socioeconomic status data: International Socio-Economic Index.", | |
| "wave_or_subset": "the sixth grade elementary school cohort", | |
| "sample_size": "2835", | |
| "unit_of_analysis": "individual - German 6th graders nested in 134 elementary school classes", | |
| "access_details": "access details are not specified; no restrictions are mentioned, perhaps the datasets are open access.", | |
| "notes": "Data were collected from a sample of students from a major European city, with about 15% of students speaking a language other than German at home. The sample is representative of public elementary school students. English achievement was assessed with a Cloze test, scaled using one-parameter item response theory in ConQuest with weighted likelihood estimates (WLEs; mean = 100, SD = 20). General cognitive abilities were measured using a composite score from two subtests of the CFT4-12R (verbal and figural analogies). All analyses used five imputed datasets to replace missing values, based on a background model including individual-level factors (grades, self-concept, interest, motivation) and classroom-level factors (achievement, socio-economic status, percentage of students with immigration background). Results were combined using MPlus 5.21 with type = imputation." | |
| }, | |
| "method": { | |
| "description": "The authors examined the effect of immigrant bilingualism on English as a foreign language achievement. They controlled for cognitive, demographic, and socio-cultural factors.", | |
| "steps": "1. Download the data and identify bilingual and monolingual groups based on language spoken at home. \n2. Exclude 111 students with no language information.\n3. Classify students into the monolingual group (n=1896) and the bilingual group (n=939).\n4. Assess English language achievement using a Cloze test, scaled with one-parameter item response theory in ConQuest using weighted likelihood estimates (WLEs; mean=100, SD=20).\n5. Measure general cognitive abilities (by the authors) using a composite score from two subtests of the CFT4-12R (verbal and figural analogies).\n6. Collect control variables from the dataset: age, gender, socio-economic status (ISEI data), parental education, and cultural capital. \n7. Handle missing data using multiple imputation.\n8. Run multiple linear regression in MPlus 5.21 with type = complex.", | |
| "models": "linear regression", | |
| "outcome_variable": "English achievement", | |
| "independent_variables": "bilingual group membership", | |
| "control_variables": "general cognitive abilities, gender, age, socio-economic status, parental education, and cultural capital", | |
| "tools_software": "For multiple regression: MPlus 5.21 taking into account the nested nature (students in classes) of the dataset (type = complex). For items scaling: ConQuest." | |
| }, | |
| "results": { | |
| "summary": "After controlling for cognitive abilities, age, gender, socio-economic status, parental education, and indicators of cultural capital, bilingual students showed a general positive trend between bilingualism and English foreign language achievement (estimate = 2.68; p < .01).", | |
| "numerical_results": [ | |
| { | |
| "outcome_name": "English achievement", | |
| "value": "2.68", | |
| "unit": "points (raw Cloze test scores scaled to mean = 100, SD = 20)", | |
| "effect_size": "not stated", | |
| "confidence_interval": { | |
| "lower": "not stated", | |
| "upper": "not stated", | |
| "level": "not stated" | |
| }, | |
| "p_value": "< .01", | |
| "statistical_significance": "true", | |
| "direction": "positive" | |
| } | |
| ] | |
| }, | |
| "metadata": { | |
| "original_paper_id": "http://dx.doi.org/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" | |
| } | |
| } | |
| } | |