Co-Principal Investigator: Roberts, Carly; Sanders, Elizabeth

Purpose: The purpose of this project is to examine the developmental trajectory of malleable reading factors (decoding, listening comprehension, and reading comprehension) among elementary school children with an intellectual disability (ID). Despite specific areas of difficulty, students with ID can learn grade-level content including reading when provided systematic and explicit instruction; however, they continue to be behind their peers with other disabilities in academic growth and achievement. These gaps are especially noticeable in reading where their skills are often lower than what is expected given their cognitive functioning. Most of the reading-related research conducted with this population is around intervention development and testing; there is limited knowledge regarding how reading skills develop over time for students with ID. This project will explore profiles of reading skill development, longitudinal predictors of reading, and home and school contexts that support reading skill development. The overarching aim of the study is to identify malleable reading factors among elementary students with ID in order to develop a literacy intervention designed to help students with ID reach their maximal potential.

Project Activities: Researchers will collect data on malleable reading factors from three cohorts of students with ID in grades 1-3 and follow the students for three years. Researchers will use this data to explore developmental trajectories of these reading factors and test predictors of growth in reading for students with ID. Researchers will also identify potential profiles of readers based on distinct clusters of trajectories and test predictors of reading profiles to inform how and when to intervene in reading. A subgroup of the students will be selected in Year 1 to participate in the following qualitative data collection activities during each year of the study (classroom literacy observation, teacher interview, and parent interview) to better understand their home and school literacy environments.

Products: The primary product of this project is preliminary evidence of the developmental trajectory of malleable reading factors in children with ID. The project will result in peer-reviewed publications and presentations as well as additional dissemination products that reach education stakeholders such as practitioners and policymakers.

Structured Abstract

Setting: The research will take place in urban, suburban, and rural elementary schools in Washington State.

Sample: Approximately 135 elementary students with ID (45 per cohort), their teachers, and their parents will participate in this research. Students in grades 1-3 will be included in the study beginning in Year 1 if they meet the following criteria: (a) have an IQ composite at least two standard deviations (SD) below the mean; (b) demonstrate levels of adaptive functioning at least two SD below the mean in any of conceptual, social, or practical skills or the composite score; (c) have an Individualized Education Program and receive special education services, (d) use 2-3 word phrases, and (e) follow directions enough to complete the assessments.

Malleable Factors: Malleable factors include decoding, listening comprehension, and reading comprehension.

Research Design and Methods: This study uses a cohort-sequential longitudinal research design along with a qualitative component. Purposeful sampling of four districts in Washington State will be conducted to recruit a diverse sample of students reflective of the demographics of students in the state. In Year 1 students in grades 1-3 will be screened for eligibility and recruited to participate in the study. Researchers will select 45 students from each grade to represent the three cohorts in this study. These students will be assessed for three consecutive years. A subgroup of the Year 1 students will be selected a priori to take part in the qualitative component of the project. Researchers will identify 24 students (six from each of four participating districts, two per grade) whose reading growth patterns differ substantially from the rest of their cohort to be included in the qualitative study. The qualitative study will entail data collection each year of the project to understand the home and school literacy environment, including classroom literacy observation, teacher interviews, and parent interviews. Data analyses will examine developmental trajectories or reading skills and test predictors of growth (decoding and listening comprehension), using data collected across the three years. Researchers will also identify potential profiles of readers based on distinct clusters of trajectories and test predictors (decoding and listening comprehension) of reading profiles.

Control Condition: Due to the nature of the research design, there is no control condition.

Key Measures: Cognitive variables will be collected using the Kaufman Brief Intelligence Test-Second Edition (verbal and nonverbal intelligence), Vineland-3 (adaptive functioning), and Comprehensive Test of Phonological Processing-Second edition (CTOPP-2; phonological memory and rapid automatic naming). Reading decoding will be assessed using the CTOPP-2 (phonemic awareness), Test of Preschool Early Literacy (concepts about print), and the Woodcock Johnson-Fourth edition (word attach and letter word identification). Listening comprehension will be measured using the Clinical Evaluation of Language Functions-Fifth edition, (CELF-5; sentence formulation and listening comprehension) and Woodcock Johnson-Fourth edition (understanding directions). Reading comprehension will be assessed using the CELF-5. Student demographic variables will be collected using school records and parent report. For the qualitative study, researchers will collect data on home and school literacy environments through observations and interviews with teachers and parents. Classroom observations will result in data on the (a) focus of instruction (b) instructional practices, (c) instructional materials, (d) teacher-student interactions, (e) student-student interactions, and (e) target student engagement. Interviews will also be conducted with each student's teacher about current instruction, influences on instruction, and perceptions of the development and goals of reading instruction for students with ID. Parent interviews will be conducted with each student's primary caregiver about the home literacy environment.

Data Analytic Strategy: Researchers will use structural equation modeling (SEM) to estimate the mean developmental trajectories for each reading factor (decoding, listening comprehension, and reading comprehension) and test predictors of growth. Researchers will use SEM growth mixture models to identify potential profiles of readers based on distinct clusters of trajectories. Researchers will use data collected in Year 1 on students' listening and decoding skills as latent predictors (across grades 1-3) of later reading comprehension as a latent outcome (across grades 3-5), controlling for grade level differences and other cognitive variables. Researchers will test for interactions among the Year 1 predictors and grade level on the outcome. Finally, to contextualize the quantitative findings, researchers will employ iterative deductive and inductive analyses of qualitative data collected on home and classroom literacy environments.