This review of published materials on transitional bilingual education programs is aimed to provide some background, understanding of the effectiveness of transitional bilingual education programs and to examine the success of these programs in leading to better performance in English and in nonlanguage subject areas as they are related to teaching and language. Educators agree that these programs need to be reviewed from time to time to prove its effectiveness or ineffectiveness in acquiring the second language. Although the term bilingual education is often applied to all instructional programs for limited English proficient students, there are three major bilingual education models: two-way bilingual education, maintenance bilingual education and transitional bilingual education. (Crawford, 1999)
Transitional Bilingual Education is an educational theory that states that children can most easily acquire fluency in a second language by first acquiring fluency in their native language. Fluency is defined as linguistic fluency (e.g. speaking) as well as literacy (e.g. reading and writing).
The goal of transitional bilingual education is to help transition a student into an English-only classroom as quickly as possible. A bilingual teacher instructs children in subjects such as math, science, and social studies in their native language, so that once the transition is made to an English-only classroom, the student has the knowledge necessary to compete with his peers in all other subject areas. The length of time a student is taught English while learning other subjects in their first language is typically three years. All instruction gradually transfers from the student's first language into English. The goals of transitional bilingual education are oral and written proficiency and academic success in English. (August & Hakuta, 1997). Research has shown that many of the skills learned in the native language can be transferred easily to the second language later.
Experts and researchers tried to define transitional bilingual education to basically clarify the term compared to the other types of bilingual education. This type of bilingual education is one in which the primary language of the students is needed for instructional support until some prescribed level of proficiency in the second language is reached. (Harris & Hodges, 1995). It is also known as early-exit bilingual education, this is the more common form of bilingual education for ELLs in the United States. (Genesee, 1999) according to (Ovando et al, 2006) this program uses the native language (L1) to teach in all subjects areas while providing the student instruction in English as a second language with a gradual transition to all English instruction.
Transitional bilingual education can be split into two major types: early-exit transitional bilingual education and late-exit transitional bilingual education. (Baker, 1993). Early-exit TBE refers to two years of maximum help using the native language, while late-exit TBE often allows around 40% of classroom teaching in the native language until the 6th grade. According to (Berman, 1992) Transitional bilingual education types lead to some advantages. Accordingly, advantages to an early-exit TBE program are that it makes sufficient use of limited bilingual teachers by concentrating them at early grades, maintains native language oral fluency, and builds bilingual communication with parents. As for the second type, late-exit TBE programs encourage proficient bilingual students and promote students' primary language literacy skills while developing a conceptual foundation for academic growth and communicating clearly to students the value of the cultural and linguistic resources they bring to school. (Commins, 1998).
Research on second language programs and transitional bilingual education programs from the 1960s through the 1990s is characterized by contradictory findings and continued professional debate. (Baker & deKanter, 1983). In reviewing the body of the previous studies found in several published materials, I tried to include studies that focus on the effectiveness on TBE programs and the success of these programs in leading to better performance in English and in non-language subject areas. There is a variety of studies showed little success in using such programs.
Studies show little effectiveness
Zirkel (1972) looked at three variations of bilingual programs in four towns. The author points out that in some cases what was termed a bilingual class in one location was indistinguishable from what had been indicated as a control class in another area. The author characterized these variations as (1) the bilingual education model and (2) the quasi-bilingual model. The children involved in the study were economically disadvantaged. The use of L1 in the classroom varied considerably in the schools included in the study, ranging from 10 to 150 minutes daily. Adjusted posttest means in both English and Spanish reading were analyzed by five tests. There was only one significant difference favoring the bilingual program in English and one in Spanish for the same group of students. This difference occurred in grades 2 and 3, which had the most English instruction. The analysis of quasi-bilingual models disclosed non-significant differences between the experimental and control groups in achievement outcomes.
As for the strengths, to partially control for the effects of nonrandom selection, Zirkel matched the experimental and comparison groups for age, sex, and socioeconomic status by eliminating students from the study until group level matching was attained. Analysis of covariance controlled for pretest and nonverbal IQ. In the discussion part, I can say that bilingual teachers in grades 2 and 3 were more qualified than first grade teachers. Therefore, teacher differences probably had a significant impact on the higher level of student achievement in grades 2 and 3.
Skoczylas (1972) reports on a title VII bilingual program for children in first grade. The bilingual education class and the comparison class came from two different schools in the same district in northern California. Each class contained native speakers of Spanish and native speakers of English. The experimental class was composed in part of the same children who had been in the bilingual kindergarten. Parents were given the option of enrolling their children in one program or another. Approximately half of the teaching day in the bilingual program was devoted to activities conducted in each of the languages. One teacher and two aids, all three bilingual, taught subject matter. Skoczylas conducted a parent survey and extensive presenting to see how the comparisons and program groups might have differed on the relevant variables age, IQ, home educational environment, school attendance, parents' educational background, language development, and sex. The two groups differed significantly on three of the background variables. The background variables were used as variants in the analysis. This analysis is one of the best we encountered for taking into account the relevant variables. Bilingual instruction did not lead to better English performance. Spanish performance of the program group was better, but math performance was worse. The author's study was limited to the first grade, so blanket generalizations to all grades are not justified.
For the strengths, the author collected extensive background information from the parents, tested for initial equivalence of the groups, and used analysis of covariance to adjust for initial differences. To discuss this study, the author found no difference between program and comparison firs-grade students in Spanish listening comprehension and English skills. The program students performed significantly better in Spanish-speaking skills and significantly worse in math.
Comparisons between different programs
Irby et al (2008) evaluated the effectiveness of a developmental bilingual education (DBE) model as compared to a transitional bilingual education (TBE) model. Irby et al made the comparison based on students learning outcomes in language and literacy acquisition in both Spanish and English longitudinally from kindergarten through second grade. This study was part of an ongoing longitudinal randomized trial project targeting Hispanic English learners' English language and literacy acquisition (project ELLA) , from kindergarten through third grade. All significant findings were in favor of the treatment group, with effect sizes ranging between .19 and .71. DBE students demonstrated statistically higher performance than TBE students on contextualized word reading fluency. Although both groups of students made meaningful gains in oral language development, the overall performance level of the treatment group was still 1.23 standard deviations between the normative value and the overall performance level of the control group was 1.65 standard deviations below the normative value. In this study, gains in English literacy acquisition appeared to influence the gain in Spanish literacy particularly for students in DBE models, as compared to students in TBE models.
Legarreta (1979) tested kindergarten children drawn from existing programs. Teacher judgment, a language use questionnaire, and pretest scores were used to limit the study to students who were essentially monolingual. Five instructional models were compared: (1) submersion, (2) ESL, (3) bilingual-concurrent translation, no ESL; (4) bilingual-balanced bilingual education, no ESL, and (5) bilingual-concurrent translation with ESL. The bilingual programs using concurrent translation were programs in which English-taught subject matter was immediately translated into Spanish. The bilingual program referred to by Legarreta as a balanced bilingual program, suing 50 percent Spanish and 50 English, can also be characterized as an alternate immersion program. The author found bilingual programs superior to traditional submersion and bilingual education programs with ESL superior to programs without ESL. Since one traditional program and ESL, it is impossible to draw any conclusions from the author's data as to the relative importance of ESL and bilingual instruction. These effects are never separated. However, he author found that children in the balanced bilingual education class, who received less English instruction than the other two bilingual education classes, outperformed those groups on two measures of English skills. The unbalanced treatments received English instruction approximately 72 percent of the time.
Regarding the strengths of this study, Legarreta's analysis is complex. Students were not randomly placed into the five types of treatment. However, analysis of covariance was used to adjust for preexisting differences. The study was restricted to monolingual, Spanish-speaking children, the type of children pertinent to transitional bilingual education theory. In the discussion part, the author found that the more instruction given in the native language, the better the performance in L1, but the next finding is not so obvious. The balanced bilinguals in the alternate immersion classroom were also found to outperform the unbalanced bilingual groups on two measures of English skills. In the case of Spanish, more instruction led to better performance. In the case of English, more instruction led to poorer performance.
Lum (1971) compared a program of English as a second language with transitional bilingual education. The students were 55 monolingual Chinese-speaking first grades in San Francisco. Chinese language arts were taught in the TBE schools but not in the ESL schools. Although a little Chinese was used in the ESL program for content-area instruction, much more was spoken in the TBE schools. Use of Chinese in both schools declined over the school year. English language arts instruction was given through ESL procedures in both schools, but the ESL-only schools average 50 percent more time each day in ESL instruction. All the teachers involved in the study were Chinese. The bilingual classes were team taught, so that one of the two teachers was expert in Chinese. The ESL classes had only one teacher per classroom. Assignments to the treatments was rather complex. First, students were screened by self-report, teacher judgments, and the Hoffman Bilingual Scale to identify only monolingual Chinese-peaking students for the study. Students who lived in one area were randomly assigned to one ESL and two TBE schools. Students living in a second attendance area were all assigned to an ESL school. There were 35 bilingual and 20 ESL students, with two ESL and three TBE classes, in reviewing the assignment process Lum concluded that subjects seemed matched through pretesting and randomization by area or residence. Lum measured oral proficiency in English using ratings of tape-recorded responses to teacher-administered stimulus pictures. Apparently, the pictures and rating method were taken from standard procedures described in the literature, although Lum's wording implies they were modified. Only one person did the scoring of the tapes. In general, free-response scoring systems are best done by multiple rates to achieve acceptable levels of reliability. The students' responses to the pictures were rated on five scales: length, response, and length of the five longest responses, number of different words used, structural complexity, and grammar. There were no differences between the groups on the last two items. On the first three measures, the English as a second language student's significantly outperformed the transitional bilingual education students. Lum converted the scores to age norms and found that the TBE students, in the first grade, functioning in English as a level equivalent to native English speaking 3- and 4- year- olds. ESL students were performing at a level equivalent to native 306- to 4.6- year- olds. Finally, Lum looked at differences between classes within each instructional method on each of the five measures. There were no significant differences among the three TBE classes on any of the five classes on one of the five variables.
As for the strengths, the project was restricted to monolingual Chinese speaker. There was a comparison of two types of instruction. Since most of the students were randomly assigned, the project was almost a true experiment. Extensive measures were used. To discuss this study, Lum's categories are somewhat misleading since the ESL classes used Chinese in their subject areas, although to a lesser degree than the TBE classes. The generalizability of Lum's findings is limited for several reasons: the absence of measures of literacy and writing, a small sample composed of one grade in one school district, the unknown reliability of the method, and the young age of the subjects.
From my review of the literature, I found that educational practices for ELL students especially BE, have been a controversial tropic for several decades. Though the judges, legislators, educators and researchers have sough to provide educational opportunities that will increase achievement for English language learners to lessen or close the achievement gap. Language acquisition and literacy development are the fundamental principles of a bilingual education program just as they are for the English immersion program. They differ in that bilingual education programs provide initial literacy instruction in a child's native language; then, those skills transfer to second language learning. Recent empirical studies suggest that ELL students have commensurate achievement in both bilingual education and English immersion programs; that both groups of ELL students are learning; that students instructed in English do better in English; that students instructed in Spanish do better in Spanish; and that English oral proficiency is a strong predictor for reading achievement.