# Presentation: 498618

## The Course of Reading Disability in First Grade: Latent Class Trajectories and Early Predictors

- Don Compton, Lynn Fuchs, and Doug Fuchs

## Criticisms of Current Learning Disabilities Definition

- Too many children are inappropriately identified
- Many children are classified as LD without participating in effective reading instruction in the regular classroom
- Too costly

## Criticisms of IQ-Achievement Discrepancy

- IQ tests do not necessarily measure intelligence
- IQ and academic achievement are not independent of each other
- In the case of word reading skill deficits, IQ-achievement discrepant poor readers are more alike than different from IQ-achievement consistent poor readers
- Children must fail before they can be identified with a learning disability

## What is Meant by an RTI Model?

- RTI refers to an individual, comprehensive student-centered assessment model. RtI is sometimes referred to as a problem-solving model. RtI models focus on applying a problem solving framework to identify and address the student’s difficulties using effective, efficient instruction and leading to improved achievement.

**Notes:**
The Response to Intervention model refers to an individual, comprehensive student-centered assessment model. RtI is sometimes referred to as a problem-solving model. RtI models focus on applying a problem solving framework to identify and address the student’s difficulties using effective, efficient instruction and leading to improved achievement. 

## Typical RTI Procedure

- All children in a class, school, district are tested once in the fall to identify student at risk for long-term difficulties.
- The response of at-risk students to GE (Tier1) is monitored to determine whose needs are not met and therefore require more intensive tutoring (Tier 2).
- For at-risk students, research-validated Tier 2 tutoring is implemented. Student progress is monitored throughout intervention. Students are re-tested following intervention.
- Those who do not respond to the validated tutoring are identified
- As LD
- For multi-disciplinary team evaluation for possible disability certification and special education placement.

## Advantages of RTI Approach

- Provides assistance to needy children in timely fashion.  It is NOT a wait-to-fail model.
- Helps ensure that the student’s poor academic performance is not due to poor instruction.
- Assessment data are collected to inform the teacher and improve instruction.  Assessments and interventions are closely linked.

## Within RTI Identification

- Tier 2 tutoring is viewed as the “test” to which at-risk students respond to determine disability.
- That response needs to be measured and categorized as “responsive” (not LD) or “unresponsive” (LD) using an appropriate tool for such measurement.

## RTI: Three Tiers

- Tier 1
- General education
-  Research-based program
-  Faithfully implemented
-  Works for vast majority of students
-  Screening for at-risk pupils, with weekly monitoring of at-risk response to general education
- Tier 2
- Small-group preventative tutoring
- Weekly monitoring of at-risk response to tier 2 intervention
- Tier 3
- Special education

## Primary Prevention:

- _Primary Prevention_:
- School-/Classroom-
- Wide Systems for
- All Students,
- Staff, & Settings

- _Secondary Prevention_:
- Specialized Group
- Systems for Students with At-Risk Behavior

- _Tertiary Prevention_:
- Specialized
- Individualized
- Systems for Students with Intensive Needs

- ~80% of Students

- ~15%

- ~5%

- CONTINUUM OF
- SCHOOL-WIDE
- SUPPORT

## RTI Tier 2: Standardized Research-Based Preventative Treatment

*Tutoring*
- Small groups (2-4)
- 3-4 sessions per week (30-45 min per session)
- Conducted by trained and supervised personnel (not the classroom teacher)
- In or out of classroom
- 10-20 weeks

## What does Tier 2 look like?Hypothetical Case Studies

## Slide 12

## Slide 13

## Slide 14

## Purpose of the Study

- To explore:
- Effects of multiple Tier 1 (classroom) and Tier 2 (pullout) instructional approaches on at-risk children’s reading growth in a 9-wk treatment period in fall of 1st grade.
- How responsiveness to the instructional approaches can be used to identify children as LD at the end of 1st grade.
- Effects of alternative methods of LD classification on prevalence and severity.
- Can characteristic growth patterns of children who are either LD and not LD be identified for Tier 1 and Tier 2 instruction?

## Reading Study Sample

- 42 1st-grade classes in 16 schools (8 Title)
- Six lowest readers from each class on WIF and RLN, with teacher corroboration (252 low-study-entry children)
- Beginning 1st grade, 6 children from each class rank ordered and, within class, split into 2 strata
- Within each stratum within each class, randomly assigned to 3 groups (*n* = 84 per condition)
- No tutoring (*n*=55 [65.5%] complete data at end grade 3)
- Fall 1st-grade tutoring (*n*=61 [72.6%] complete data at end grade 3)
- Spring 1st-grade tutoring, but only with inadequate slope/final intercept for fall 1st grade (*n*=64 [76.2%] complete data at end grade 3)
- Three groups comparable demographically and on RLN, WIF, IQ, WRMT WID/WA, TOWRE SW/PD
- 18 weekly Word Identification Fluency measurements
- End of 3rd grade, disability: <85 on latent variable of word reading, nonsense word reading, comprehension

## Evidence-Based Tutoring

- Tutoring
- Letter-Sound Recognition
- Phonological awareness and decoding
- Sight Words
- Fluency
- Four Groups
- Fall Tutoring (n=61)
- Spring Tutoring for Nonresponsive Children (n=32)
- Spring No Tutoring for Responsive Children (n=32)
- Controls (No Tutoring, n=55)
- Sessions
- Conducted by research assistants
- 2-4 students per group
- 4 sessions/week
- 45 minutes/session
- For a total of 36 sessions of tutoring

## Questions

- Identify 1st-grade growth trajectories characteristic of later disability versus ND
- Examine effects of 1st-grade tutoring on trajectories
- Explore cognitive profiles associated with each latent class

## General Model for Identifying Trajectory Classes 

## Analysis Plan

- Conventional growth modeling to evaluate appropriateness of the hypothesized quadratic model
- Multiple group growth mixture modeling with a distal latent factor (F, at end 3rd grade in reading; end 2nd grade in math) and beginning 1st-grade covariates to identify disability and nondisability populations within each known group.
- Distal latent factor was regressed on the categorical latent variable (C), representing subpopulation CBM growth characteristics in 1st grade.
- Subpopulation variable (C) was regressed on the known class variable (CG).
- Growth parameters (I, S, Q) and C were regressed onto the time-invariant covariates.

## Estimated Parameters of Interest

- Average latent class probabilities: likelihood each individual belongs to each class
- Class-specific profiles: likelihood each individual in the class scores above/below criterion for disability on distal latent class indicator
- Means/variances on
- Growth parameters (I,S,Q)
- Beginning 1st-grade performance
- Cognitive predictors
- End-study performance as function of known class and disability/nondisability trajectory class
- Class-specific probabilities for categorical latent variable as function of the covariates

## Data Analysis

- Growth model analyses with Mplus 4.0
- Model estimation used maximum likelihood estimator with robust standard errors
- CBM data centered on initial assessment
- Mplus missing data module (maximum likelihood missing at random estimation procedures)
- Estimated starting values derived from multiple group analysis of growth using only the CBM data
- Covariates centered on grand means

## Results: Conventional Growth Modeling 

- Word identification fluency (WIF)
- 18 weekly across fall and spring
- Quadratic model improved overall fit of model over linear model
- I: 14.20 words (SE=0.719; *z* = 19.74)
- S: 1.80 words per week (SE=0.138; *z* = 13.09)
- Q: -0.015 words2 per week (SE=0.006; *z* = -2.31)

## Results: Fall Tutoring

## Results: Spring Tutoring Necessary

## Results: Spring Tutoring Unnecessary

## Results: Control

## Results: Growth Mixture Modeling

- For each trajectory class, intercept and slope was significantly greater than zero and necessary for describing growth.
- Quadratic term significantly different from zero only for
- Fall tutoring (*z* = -2.574)
- Spring tutoring-necessary (*z* = 4.346)

## Average Probability of Latent Class Assignment and Class-Specific Profiles on the

* **Distal Reading Latent Class Indicators*

|  |  |  | 
Class-Specific Probabilities
on Latent Class Indicatorsb |  |  |
| --- | --- | --- | --- | --- | --- |
| Latent Class | Latent Class Probabilitya |  | WRMT-R
WID | WRMT-R
WA | WRMT-R
PC |
| Fall Tutoring RD | .964 |  | .022 | .501 | .005 |
| Fall Tutoring NRD | .995 |  | .954 | .999 | .833 |
| Spring Tutoring Necessary RD | .942 |  | .242 | .934 | .071 |
| Spring Tutoring Necessary NRD | .993 |  | .985 | 1.000 | .941 |
| Spring Tutoring Unnecessary RD | .943 |  | .826 | .995 | .534 |
| Spring Tutoring Unnecessary NRD | .927 |  | 1.000 | 1.000 | 1.000 |
| Control RD | .912 |  | .571 | .983 | .242 |
| Control NRD | .952 |  | .984 | 1.000 | .937 |

## Results: Growth Mixture Modeling(across entire sample)

- Average latent class probability: Probability child is assigned to correct disability trajectory class within the known class: .912 to .995 (precise)
- Class-specific profiles on 3rd-grade latent class indicators of disability (WID, WA, PC): Probability child in that class would score > 85
- WA: Across disability groups, poor precision.
- WID and PC: More consistently distinguished RD from ND.
- For spring tutoring-unnecessary RD group, class-specific probabilities indicate this class does not have a characteristically RD profile.
- For control RD group, high class probability of scoring normal on WID, but low class probability of scoring normal on PC. So, poor reading comprehension is the defining characteristic of untreated at-risk students.

## Estimated Multinomial Regression of Latent Class Variable on Covariates

## Estimated Multinomial Regression of Latent Class Variable on Covariates

## Plots represent estimated class-specific probability of class membership as function of one covariate, while keep other covariates constant

- Sound matching and vocabulary distinguished latent class membership, but only in control group.
- Control students with lower sound matching scores have greater probability of being assigned to control RD class.
- Control students with higher vocabulary scores have greater probability of being assigned to control ND class.

## Conclusions

- First-grade trajectory classes associated with 3rd-grade disability status can be identified with high precision using WIF. So, WIF can be used for 1st-grade progress monitoring within RTI, as an indicator of long-term RD status.
- In control (untreated) group, RD and ND trajectory classes had same intercept, but vastly different slopes. So, slope can be used to index responsiveness.
- Only 2 classes had significant quadratic term.
- For fall tutoring, growth decelerated across year.
- For spring tutoring-necessary, growth accelerated across year.

## Conclusions

- 3rd-grade WID and PC measures distinguished RD from ND; WA did not.
- Spring tutoring-unnecessary NRD was a relatively pure group of NRD students. So, using WIF in fall semester of 1st grade to select children at-risk students may be efficient.

## Conclusions

- For control RD students, reading comprehension skill was defining characteristic. Interesting because 1st-grade trajectory classes  formed exclusively with WIF. Also, no way to distinguish control RD and NRD using intercept.
- 1st-grade cognitive predictors most useful for untreated students. For control students, low sound matching associated with RD; high vocabulary associated with NRD.
- Within treated students, RTI (trajectory class) was what distinguished RD from NRD, effectively overriding initial individual differences on sound matching and vocabulary.

## Thank You