The federal law for special education (Individuals with Disabilities Education Improvement Act, 2004) requires that states develop and implement eligibility criteriafor categories of special education services. However, evidence-based differential diagnosisof specific kinds of developmental disabilities or learning disabilities is not mandated or defined. Categories for service delivery and diagnoses are not the same (for further discussion of the distinction between eligibility and diagnosis and the educational implications of this distinction, see Berninger & Holdnack, 2008). Although Chapter 504 of the Americans with Disabilities Act (1990, 2008) requires accommodations for educational handicapping conditions, no evidence-based diagnoses of these educational handicapping conditions are specified in this federal law as well. Moreover, how eligibility decisions for special education or accommodation decisions are made and implemented varies widely across and within states and cases. The only constant is widespread lack of attention to careful diagnosis and treatment-relevant diagnosis, which is particularly concerning at a time when the pertinent research findings for diagnosis and treatment of specific kinds of disabilities are accumulating rapidly.

The result of current identification practices is that many students with language problems are not receiving appropriate services. These language problems occur in the context of either a profile of developmental disabilities in which one or more of the developmental domains-cognitive, language, sensory motor, social emotional, or attention/executive functions-fall outside the normal range or a profile of specific learning disabilities in which, despite overall development falling within the normal range in each of those five development domains, specific language or other processes interfere with learning. Further complicating the issue of meeting the needs of both students with and without developmental disabilities is that they often also have language or related problems for which they are often referred for assessment to professionals with different disciplinary training and expertise. These individuals may or may not make it clear to parents and other professionals whether development in general or a specific area of development may fall outside the normal range. Also, they typically do not use common terminology or assessment measures for defining what the language or other problems are or draw on common knowledge about what appropriate intervention/treatment, therapy, or instruction might be.

At least three factors have probably contributed to insufficient dialogue across disciplines and professions about these issues.

1. Despite serving the same or similar clients professionally, professionals in the oral language, reading, and writing domains or in the related fields of speech-language pathology and audiology may know little of the history, traditions, and concepts of the other disciplines regarding research and practice (including language issues). There is an urgent need for cross-disciplinary dialogue that should seek to close this gap by pursuing agreement on how terminology is used and its relationship to research on diagnosis and treatment.

2. Referral bases may vary significantly depending on the setting where practitioners provide professional services. An outcome is that professionals in different disciplines develop, based on their practitioner experience, different implicit theories about language disabilities that can occur in the context of a variety of kinds of developmental and learning disorders.

3. Many factors that could affect recommendations for implementing research findings in practice have not been adequately examined. Researchers may operate with different theoretical frameworks, ask different kinds of research questions, use different methods, and acquire different kinds of samples with different participant characteristics, depending on the investigator's disciplinary preparation and experience as researcher, practitioner, or other professional role.

One goal of this issue, therefore, is to initiate a dialogue between professionals in speech-language pathology, whether they work in schools or nonschool settings, and psychologists and educators about how we might create cross-disciplinary conceptual frameworks that draw on our collective expertise so as to serve students with language problems more effectively. A related goal is to encourage speech--language pathologists (SLPs) to think more deeply about the written language problems that students may have in addition to oral language problems or even in the absence of oral language problems. Although many SLPs now receive graduate preparation in both oral and written language, their education may emphasize the former compared with the latter. In contrast, psychologists and educators often receive relatively more training in written language than oral language and, sometimes, relatively little training in the disorders of either oral or written language.

To achieve these goals, the introductory article, "Cross-Disciplinary Dialogue About the Nature of Oral and Written Language Problems in the Context of Developmental, Academic, and Phenotypic Profiles," is coauthored by the guest editors, who are an SLP and a psychologist, respectively. Yet, both also have education and expertise in sociolinguistics, psycholinguistics, child language, and literacy, plus considerable clinical experience in assessing and treating children and youth with oral language and/or written language problems with or without developmental disabilities. An approach to treatment-relevant, diagnostic assessment that takes the context of a profile of relevant skills into account emerged from their cross-disciplinary dialogue and is described and discussed in their article.

In the next three articles, three SLPs, who are both educators and clinicians, explore written language problems in individuals who may also have oral language problems or vice versa. Scott, in "Assessment of Oral Language and Literacy: A Process of Hypothesis Testing for Individual Differences," makes a compelling case for the clinician adopting a thinking mode that takes into account each individual's unique language learning needs across oral or written modalities, rather than focusing exclusively or narrowly on special education eligibility criteria. These needs may include weaknesses or impairment in syntax, but not always: Word-level skills (vocabulary or word retrieval) or discourse-level skills (e.g., understanding stated or inferred information) may also be weak, not only for oral language but also for reading and/or writing. Troia makes a valuable contribution in reminding SLPs that pragmatic use of language for social functions is as relevant to written language as it is to oral language. He raises the educationally relevant question of "How might pragmatic language skills affect the written expression of students with language impairments and learning disabilities?" Next, Apel and Apel, in their article, "Identifying Intraindividual Differences in Students' Written Language Abilities," propose six kinds of linguistic knowledge-phonology, orthography, morphology, semantics, syntax, and pragmatics-which should be assessed because they are relevant to learning to read and write. Their article reinforces the kind of clinical thinking described in the previous articles, which empowers diagnosticians to go beyond restricting assessment to eligibility criteria for special education services to expanding to full assessment of an individual's language profile of strengths and weaknesses. The full profile is relevant to planning and implementing appropriate oral and written language services in schools, including general and special education, and other settings for students who may or may not have other kinds of disabilities or learning needs in addition to language problems.

Finally, and of considerable relevance, Foorman, Arndt, and Crawford bring to the cross-disciplinary conversation the voice of educators with research and practitioner expertise in assessing and teaching reading and related literacy skills. The teaching profession is probably the one most likely to make a difference in the educational outcomes for students with language problems because teachers spend more time than any other profession in providing the daily instructional program. These authors discuss "important constructs in literacy learning across disciplines," which should be taken into account by the SLPs, educators, and psychologists who participate in multidisciplinary teams in schools or provide assessments from their discipline's perspective in nonschool settings.

Collectively, these articles provide perspectives to consider as the dialogue continues on how professionals across disciplines can most meaningfully and effectively integrate their disciplinary perspectives in serving students who have language problems with or without other developmental or learning disabilities. In addition, each article contributes to the broader purposes of the issue. These purposes are to (a) bring clarity to the controversies over defining what a language impairment is and how to treat it (e.g., Butler & Silliman, 2002; Silliman & Mody, 2008; Silliman & Wilkinson, 2004; Stone, Silliman, Ehren, & Apel, 2004); (b) propose conceptual models to assess intraindividual differences in the language learning profiles of children struggling with oral and/or written language; (c) link assessment results to instruction in school or clinical settings, and (d) develop terminology and concepts for cross-disciplinary dialogue and collaboration to improve affected individuals' language learning and language use in school and other settings.

Elaine R. Silliman, PhD

Virginia W. Berninger, PhD

Issue Coeditors

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