An examination of an implementation of the simple difference score distribution model in learning disability identification

An important part of the PL 94–142 learning disability (LD) definition is the requirement that a child manifest a discrepancy between ability and achievement to be eligible for special education services. Because the language used in PL 94–142 is generic, it has been left to each state to determine how this discrepancy criterion is to be implemented. Subsequently, numerous discrepancy formulas have been proposed, and many of them have been rejected as statistically unsound. In response to this professional paralysis, and faced with continued increasing LD enrollment, the California State Legislature took matters into its own hands and passed legislation mandating the use of the simple difference score distribution model as part of the state LD eligibility criteria. This study examines the implementation of this procedure in six California school districts. The results revealed that the IEP teams' placement decisions were influenced by the students' discrepancy scores, but that prereferral status (initial evaluation vs. reevaluation) was a better predictor of postevaluation special education status. Shortcomings of this discrepancy procedure and implications for the IEP team decisionmaking process are discussed.     

Effects of simple and regressed discrepancy models and cutoffs on severe discrepancy determination

Concern over the growing number of students identified as learning disabled has led school districts to examine the criteria for determination and the means by which they are operationalized. Two frequently used methods for determining a severe discrepancy between ability and achievement, a key criterion in LD determination, were applied to a sample of 344 students to determine how a change in method might influence the rates and characteristics of students meeting this criterion. The results indicate an increase in numbers when a regression method is used over a simple difference score method. When the change proposed included moving to a more severe cutoff score, the pattern reversed and a 20% decrease was observed. Although IQ correlated with the discrepancies when the simple difference score method was used, no correlation was observed when regression was employed, indicating that regression may be a more equitable method for calculating severe discrepancies. Neither method resulted in disproportionate racial representation among those meeting the severe discrepancy criterion.     

Students classified as LD who received course substitutions for the college foreign language requirement: a replication study

This replication study examined whether 158 college students classified as learning disabled (LD) who were granted course substitutions for the foreign language (FL) requirement would display significant cognitive and academic achievement differences when grouped by levels of IQ-achievement and achievement-achievement discrepancy and by level of performance on an FL aptitude test (Modern Language Aptitude Test; MLAT), phonological/orthographic processing measures, and in FL courses. The results showed that there were few differences among groups with differing levels of IQ-achievement or achievement-achievement discrepancy (i.e., < 1.0 SD, 1.0-1.49 SD, and > 1.50 SD) on MLAT and American College Testing (ACT) scores, graduating grade point average (GPA), or college FL GPA. The results also showed that between groups who scored at or above versus below the 15th percentile (i.e., < 1.0 SD) on the MLAT, there were no differences on measures of graduating GPA, college FL GPA, native language skill, ACT score, and Verbal IQ. Demographic findings showed that 44% of these petition students met a minimum IQ-achievement discrepancy criterion (> or = 1.0 SD) for classification as LD. These findings suggest that many traditional assumptions about LD and FL learning are likely to be false.     

Students classified as LD and the college foreign language requirement: a quantitative analysis

This study was conducted to determine whether students classified as learning disabled (LD) who were permitted to substitute courses for the college foreign language (FL) requirement at one university would display significant cognitive and academic achievement differences when grouped by level of discrepancy between IQ and achievement, by discrepancy between achievement according to different measures, and by level of performance on phonological-orthographic processing measures, on the Modern Language Aptitude Test (MLAT), and in FL courses. Results showed that there were no differences among students with different levels of discrepancy (i.e., < 1.0 SD, 1.0-1.49 SD, and > 1.50 SD) on MLAT and American College Testing (ACT) scores, graduating grade point average (GPA) or college FL GPA. Results also showed that among students who scored below versus at or above the 25th percentile on phonological-orthographic processing measures, there were no differences on measures of IQ, ACT, MLAT, and GPA, as well as most measures of academic achievement. Implications for the use of the LD label to grant FL course substitutions or waivers, use of the MLAT in the diagnostic and course substitution/waiver process, and the validity and reliability of traditional criteria for the classification as LD are discussed.     

Comparison of students classified as LD who petitioned for or fulfilled the college foreign language requirement

In this study, we compared the cognitive, academic achievement, and demographic profiles of 46 students from one university who had been classified as learning disabled (LD) and had received permission to substitute courses for the university's foreign language (FL) requirement (petition group) with the profiles of 21 students from the same university who had been classified as LD and had fulfilled the university's FL requirement by passing FL courses (nonpetition group). Results showed no significant differences between the two groups on measures of reading, mathematics, written language, American College Testing score, and graduating grade point average when IQ was used as a covariate. More petition than nonpetition students had at least a 1.0 SD discrepancy between IQ and achievement and had been referred only for FL learning problems. More nonpetition than petition students had taken an FL in college and received accommodations in the FL. The two groups together appeared to constitute a heterogeneous group of learners, with more than half failing to meet a minimum discrepancy criterion for classification as LD. The discussion addresses the classification system for LD, the process for determining the presence of FL learning problems and how to address them, and directions for further research.     

Extrinsic and intrinsic factors in graduation and academic failure among LD college students

A group of 110 LD college students were compared to a random stratified sample (RSS) of 153 peers attending the same moderately selective college between 1980 and 1988. The LD students received comprehensive, highly coordinated support services for at least one semester. The groups were matched on gender, college experience, semester, and year of entry to the college. The LD and RSS groups were compared on high school preparation and performance, ACT and college performance, and graduation and academic failure rate. Although the LD students’ high school records, ACT scores, and college performance were inferior to that of the RSS group, they graduated at the same rate and within the same time frame. Neither was there any significant difference in the academic failure rate. Closer examination of the LD graduates and academic failures’ performance showed that in spite of the similarities in intellectual abilities, academic achievement, and aptitude-achievement discrepancy, two factors differentiated between the LD graduates and non-graduates: oral language abilities and motivation and attitude toward the teaching-learning process. These two factors accounted for 60 percent of the variance in graduation status. This research was supported in part by grants from the Butz and Thorn River Foundations.     

Discrepant team decisions: The effects of race,gender, achievement,and IQ on LD eligibility

To determine whether student characteristics might influence the misclassification of pupils with respect to LD status, the racial, gender, intellectual, achievement, and grade-level status of 344 subjects who had been referred for LD diagnosis was examined. In one fourth of the cases, students were declared either eligible without a severe discrepancy or ineligible with a severe discrepancy regardless of method used (standard score vs. regressed standard score) or cutoff value employed (15-point vs. 22-point discrepancy). Being White, older, and of higher intelligence and achievement were characteristics of those found ineligible despite a severe discrepancy. Being female and less academically able were characteristics of those declared eligible without a severe discrepancy. Implications are presented.     

DEFINING THE UNDEFINABLE: OPERATIONALIZATION OF METHODS TO IDENTIFY SPECIFIC LEARNING DISABILITIES AMONG PRACTICING SCHOOL PSYCHOLOGISTS

Accurate and consistent identification of students with specific learning disabilities (SLDs) is crucial; however, state and district guidelines regarding identification methods lack operationalization and are inconsistent throughout the United States. In the current study, the authors surveyed 471 school psychologists about school SLD identification guidelines and the identification methods actually used (e.g., ability‐achievement discrepancy, response‐to‐intervention, and the evaluation of students’ pattern of strengths and weaknesses). Results indicated that nearly half the participants were allowed or required to choose the method of identification that ensured students received services, if the school‐based team determined services were warranted. Variations in SLD identification methods were also found between schools with different characteristics (e.g., location, school level, and student composition). Implications for practice are discussed.     

Differential ability scales: Profiles of learning-disabled subtypes

The purpose of this study was to determine whether distinct subgroups of children with learning disabilities could be identified using a single, recently developed instrument—the Differential Ability Scales (DAS). Ward's method of cluster analysis was used to group 83 school-verified children with learning disabilities from the standardization sample. The following six subgroups were identified: (a) generalized, (b) high functioning, (c) normal, (d) underachievement, (e) borderline, and (f) dyseidetic. Not all subgroups displayed the expected discrepancy between intelligence and achievement associated with the current definitions of I.D. In subsequent discriminant analyses, both achievement and diagnostic subtests were necessary for accuracy in classification. This study provided evidence of the DAS's ability to diagnose the learning disabled differentially and provided distinct profiles for LD subgroups. Administration of the diagnostic subtests along with achievement subtests can provide the clinician with valuable diagnostic information for LD.     

The Ability–Achievement Discrepancy: Does it Contribute to an Understanding of Learning Disabilities?

Federal legislation of the 1960s and 1970s extending educational services to learning disabled children contained a criterion requiring a severe discrepancy between an child's ability and achievement. Following a discussion of the historical context related to this decision, research related to discrepancy is reviewed using reading disabilities or dyslexia as the prototype. Topics examined include the relationship of IQ to various factors, including underlying cognitive weaknesses; varying IQ levels; stability of diagnosis; heterogeneity of the diagnostic category; genetic and neuroimaging findings; and appropriate standards of comparison. Research on the practical application of the discrepancy model is also reviewed. In general, there is little evidence to support its continued use. Three proposed alternatives are considered, and a possible model is offered that incorporates findings from research on diagnosis and intervention.     

Sex bias in the diagnosis of learning disabled students

Studies of special education students consistently indicate a preponderance of males in classrooms for the learning disabled (LD). To determine whether the overrepresentation of males and underrepresentation of females constitutes sexual discrimination, an objective index involving the discrepancy between expected and actual achievement was calculated for each student. Factors such as intelligence, socioeconomic status, and reason for referral also were investigated to help explain the large disparity of boys to girls diagnosed and placed as LD. Data were collected on 235 LD students and 290 students referred for special education who were declared not impaired (NI). No evidence was found to indicate that group membership in a sexual class was related to diagnostic and placement practices. Approximately one half of the students labeled as LD did not show a reliable discrepancy between expected and actual achievement.     

Responsiveness‐to‐Intervention: Definitions,Evidence, and Implications for the Learning Disabilities Construct

Longstanding concern about how learning disabilities (LD) are defined and identified, coupled with recent efforts in Washington, DC to eliminate IQ‐achievement discrepancy as an LD marker, have led to serious public discussion about alternative identification methods. The most popular of the alternatives is responsiveness‐to‐intervention (RTI), of which there are two basic versions: the “problem‐solving” model and the “standard‐protocol” approach. The authors describe both types, review empirical evidence bearing on their effectiveness and feasibility, and conclude that more needs to be understood before RTI may be viewed as a valid means of identifying students with LD.     

Responsiveness to General Education Instruction as the First Gate to Learning Disabilities Identification

Most definitions of learning disabilities (LD) include a qualification that adequate general education instruction was received and the child with LD did not benefit. Rarely is this tenet assessed in either practice or research before a diagnosis is made. We review three studies that investigated children's responsiveness to general education reading instruction as an indicator of need for more intensive interventions. Adequacy of instruction was quantified by children's level and rate of progress, compared to classmates, as measured by curriculum‐based measures of oral reading fluency. We found that the response‐to‐instruction model tested was valid in that (1) children who differ from their peers on level and slope of performance (dual discrepancy) have more severe academic and behavioral problems than children who have IQ‐achievement discrepancies or low achievement; (2) children who demonstrate persistent nonresponsiveness over three years differ from other at‐risk children on reading, reading‐related, and behavioral measures; and (3) at‐risk children who participated in specially designed general education interventions had better outcomes than at‐risk children who did not participate. We conducted additional analyses to assess low achievement definitional variations and found that they lack sensitivity and coverage compared to a dual discrepancy definition.     

Substance use, substance abuse, and LD among adolescents with a childhood history of ADHD

A clinic-referred sample of 109 children with attention-deficit/hyperactivity disorder (ADHD) was followed into adolescence for the ascertainment of alcohol and other drug use and abuse. Learning disability (reading or math) in childhood was examined as a predictor of adolescent substance use and substance use disorder for alcohol and marijuana. No statistically significant group differences for children with LD versus those without LD emerged even after using different methods to compute LD. IQ/achievement discrepancy scores were similarly not predictive of later use or abuse. However, children with ADHD who had higher IQs and higher levels of academic achievement in childhood were more likely to try cigarettes, to smoke daily, and to have their first drink of alcohol or first cigarette at an early age. Children with ADHD who had higher reading achievement scores were less likely to have later alcohol use disorder. Although these findings are necessarily preliminary, due to the small number of children interviewed, the pattern of results suggests that level of cognitive functioning--rather than discrepancy between IQ and achievement--is important for the prediction of later substance use and abuse, at least in this clinic-referred sample of children with ADHD. Further, different mechanisms of risk related to cognitive functioning may be operating for experimentation with legal drugs such as alcohol and tobacco, regular cigarette smoking, and problematic alcohol use.     

天才学习不良学生的评估与诊断

对天才学习不良学生的评估需要同时考虑天才与学习不良的标准,但由于天才学习不良的定义本身不清晰,使得对它的鉴定缺乏明确的标准。已有研究提出的标准主要涉及天才、能力一成绩差异和加工能力缺陷三个方面。目前对天才学习不良学生的鉴定主要是理论层面的探讨,实践研究很少。多数的研究主张综合运用多种方法来鉴定天才学习不良群体。未来的研究应集合天才领域与学习不良领域的专家,将对天才学习不良学生的诊断与干预结合起来,更好地为这一群体提供需要的服务。     

International Approaches to Learning Disabilities: More Alike or More Different?

This special issue deals with the identification and remediation criteria/practices employed in several countries regarding learning disabilities (LD). An analysis of the identification criteria suggests that most countries follow early law mandates of the United States (e.g., PL 94–142) regarding the definition of the disorder and use the classical discrepancy between potential and achievement model for identification purposes (with few exceptions). Several countries reported the absence of standardized assessments and experts who can deal with the disorder, a fact that is more prominent in countries that have to deal with the education of minority/immigrant groups. Multicultural, political, linguistic, and economic factors seemed to influence both the identification practices and also the remediation services (quality and availability). By closely examining the factors deemed important for students with LD, it was obvious that most authors pointed to the importance of socio‐emotional variables. I concluded that these latter factors may be accountable, to a large extent, for the experience of students with LD at school and close attention needs to be paid to them.     

Academic underachievement among children with epilepsy: proportion exceeding psychometric criteria for learning disability and associated risk factors

This study assessed rates of learning disabilities (LD) by several psychometric definitions in children with epilepsy and identified risk factors. Participants (N = 173, ages 8-15 years) completed IQ screening, academic achievement testing, and structured interviews. Children with significant head injury, chronic physical conditions, or mental retardation were excluded. Using an IQ-achievement discrepancy definition, 48% exceeded the cutoff for LD in at least one academic area; using low-achievement definitions, 41% to 62% exceeded cutoffs in at least one academic area. Younger children with generalized nonabsence seizures were at increased risk for math LD using the IQ-achievement discrepancy definition; age of seizure onset and attention-deficit/hyperactivity disorder (ADHD) were risk factors for reading and math LD using low-achievement definitions. Writing was the most common domain affected, but neither ADHD nor seizure variables reliably identified children at risk for writing LD. Although children with earlier seizure onset, generalized nonabsence seizures, and comorbid ADHD appear to be at increased risk for some types of LD by some definitions, these findings largely suggest that all children with epilepsy should be considered vulnerable to LD. A diagnosis of epilepsy (even with controlled seizures and less severe seizure types) should provide sufficient cause to screen school-age children for LD and comorbid ADHD.     

A nationwide epidemiologic modeling study of LD: risk, protection, and unintended impact

Through multiple logistic regression modeling, this article explores the relative importance of risk and protective factors associated with learning disabilities (LD). A representative national sample of 6- to 17-year-old students (N = 1,268) was drawn by random stratification and classified by the presence versus absence of LD in reading, spelling, and mathematics according to ability-achievement discrepancies or low achievement levels. The dichotomous classifications were regressed on sets of explanatory variables indicating potential biological, social-environmental, and cognitive factors, problem behavior, and classroom learning behavior. Modeling revealed patterns of high risk for male students and students evincing verbal and nonverbal ability problems and processing speed problems. It was shown that, absent controls for cognitive abilities (such as provided by the ability-achievement discrepancy definition), definitions keyed to low achievement will substantially overidentify ethnic minority and disadvantaged students and will be confounded by significantly higher proportions of students who display oppositional and aggressive behavior problems. Alternatively, good learning behaviors uniformly provide substantial reduction in the risk for LD.     

Educational Programs for Elementary Students with Learning Disabilities: Can They Be Both Effective and Inclusive?

One of the most controversial issues in special education over the last 40 years has been the extent to which students with learning disabilities (LD) should be educated in general education classrooms. Recent mandates in federal law requiring that all students with disabilities have access to the general education curriculum and make adequate yearly progress relative to this content have intensified this debate. In this article, a brief summary of research regarding the nature of instruction that produces significantly improved educational outcomes for students with LD is provided. This is followed by a review of research related to the delivery of this high‐quality instruction in inclusive, general education classrooms and in resource settings. We conclude that this research provides the foundation for reconsidering full inclusion and how services are delivered for elementary students with LD.     

阅读困难诊断标准与模式的“后智力—成就差异”趋势

阅读困难是学习困难研究中最受关注的一个领域,对整个学习困难研究领域具有重要影响。对阅读困难的有效诊断是阅读困难的研究和干预的基础。在阅读困难的诊断中,曾经广泛应用的智力—成就差异标准与模式在有效性、敏感性以及对干预的指导意义等方面存在严重不足,受到越来越多研究者和实践者的屏弃。目前,核心技能缺陷和干预—应答两类诊断标准和模式日益受到关注和采纳。我国迄今较少系统研究阅读困难的诊断标准与模式,不过,有关汉语阅读困难的初步研究鉴别出语音缺陷、快速命名缺陷和语素技能缺陷,为发展和应用核心技能标准和模式提供了重要基础,也为建立干预—应答模式提供了参考。确立汉语阅读困难诊断的核心技能与干预—应答标准与模式还有待系统和深入的研究。