Research regarding typical English language development in children who are bilingual is of interest for speech-language pathologists, but often this information is not available to them. As a result, many individuals find themselves believing false stereotypes about children who are bilingual, such as the idea that bilingualism causes developmental delay or disorders. For example, individuals do not realize the differences in past tense development for bilingual children versus monolingual children, a form that is often difficult for monolingual English-speaking children with developmental language delays. By focusing on a specific aspect of language development, such as English past tense acquisition of children who are bilingual, and observing changes in MLU and grammaticality that accompany acquisition, this study seeks to increase the existing knowledge on bilingualism and language development. Specifically, we will answer the following questions: a) At which grade level do Spanish-English bilingual children master English past tense after they enter English-only schooling in preschool? b) What types of errors do the children make with regular past tense? c) what types of errors do they make with irregular past tense? and d) What is the level of English grammaticality and MLUw at each grade level in English after children enter preschool? This study examined past-tense accuracy, MLU, and grammaticality development over a period of 5 years, in 13 children who were participants in a larger project called the Language and Reading Research Consortium (LARRC). Children were followed from preschool to third grade. They provided a yearly language sample by retelling one of the wordless Marianna Meyer and Mercer Meyer frog books, such as Frog on His Own or A Boy a Dog a Frog and a Friend. The language samples were then transcribed, coded, and analyzed using the Systematic Analysis of Language Transcripts (SALT) software. Results indicate that children progressively improved over the years, with children reaching over 80% accuracy with past tense by year 3 or first grade; they demonstrated the most improvement in MLU between years 2 to 3 and years 3 to 4; and they showed a gradual improvement in grammaticality each year, with the exception of no increase between years 4 to 5. Findings from the study indicate that there is leveling in all three areas after 2nd grade. These results contribute to our understanding of normal English language development in bilingual children and may improve assessment when we evaluate their performance in English as a second language.

Preschoolers' vocabularies are an important component of their receptive and expressive language skills. This study was designed to catalog preschoolers' expressive vocabularies to provide an accurate estimate of how many words and which words seven preschoolers knew. In this study a LENA digital recorder was used to record language samples of the children (age range 40 months to 69 months) over 4-6 days. Their language samples were transcribed and individual root words were extracted. The children spoke an average of 1,698 unique words (range 1,522 \u2014 1,957 words). There were 539 words produced by all of the children in the study as well as 820 words produced by 6 of the 7 children. These data provide preliminary information that will be useful for designing a larger, more comprehensive study of children's vocabulary with the goal of teachers and speech-language pathologists being able to use this information to determine if a child's vocabulary is smaller than other children when they enter elementary school. This can inform assessment and intervention decisions as well as provide guidance to preschool curriculum developers.

EMBRACE (Enhanced Moved By Reading to Accelerate Comprehension in English) is an IPad application that uses the Moved By Reading strategy to help improve the reading comprehension skills of bilingual (Spanish speaking) English Language Learners (ELLs). In EMBRACE, students read the text of a story and then move images corresponding to the text that they read. According to the embodied cognition theory, this grounds reading comprehension in physical experiences and thus is more engaging.

In this thesis, I used the log data from 20 students in grades 2-5 to design a skill model for a student using EMBRACE. A skill model is the set of knowledge components that a student needs to master in order to comprehend the text in EMBRACE. A good skill model will improve understanding of the mistakes students make and thus aid in the design of useful feedback for the student.. In this context, the skill model consists of vocabulary and syntax associated with the steps that students performed. I mapped each step in EMBRACE to one or more skills (vocabulary and syntax) from the model. After every step, the skill level is updated in the model. Thus, if a student answered the previous step incorrectly, the corresponding skills are decremented and if the student answered the previous question correctly, the corresponding skills are incremented, through the Bayesian Knowledge Tracing algorithm.

I then correlated the students’ predicted scores (computed from their skill levels) to their posttest scores. I evaluated the students’ predicted scores (computed from their skill levels) by comparing them to their posttest scores. The two sets of scores were not highly correlated, but the results gave insights into potential improvements that could be made to the system with respect to user interaction, posttest scores and modeling algorithm.