Identifying Young Children with Language Impairments: Measurement Issues Mabel L. Rice

1. Identifying Young Children with Language Impairments: Measurement IssuesMabel L. Rice Presentation at ASHA Conference for Speech-Language Pathologists in Schools  Nashville, Tennessee Saturday, July 13, 2002

2. The Problem of Identification • Kindergarten children with Specific Language Impairments (SLI) can be difficult to identify (cf. Only 29% of kindergarten children known to have SLI were enrolled in intervention; Tomblin et al., 1997) • Variation in rates of language acquisition among young unaffected children adds to the complexity of identification of affected children

3. Conventional Measures, and the Normal Curve Assumption for Language Assessment • Assumption of an age-referenced normal distribution of children on a general language dimension

4. Number of Children Performance Level

5. Related properties • About 16% score 1 SD or more below the mean • About 2% score 2 or more SD below the mean • About 66% score within 1 SD of the mean

6. Positive applications • Determine the prevalence of SLI (about 7% in 5-year-olds; Tomblin et al., 1997) • Determine the likelihood of speech impairments with language impairment (less than 2% in the general population of 5-year-olds; Tomblin et al., 1997) • Determine long-term prognosis (individuals are likely to remain in the low levels of performance; Johnson et al., 1999)

7. Limitations • No intrinsic cut-off score for “affected” • No obvious way to interpret the test score in terms of particular linguistic content • No way to interpret a child’s progress toward the adult grammar

8. A Grammatical Marker Approach • Obligatory properties of clausal structure • These balls/*these ball • She is walking/*she walking • She walks outside/*she walk outside • Yesterday she walked outside/*yesterday she walk outside • Does she like to walk?/*she like to walk?

9. Distributional Properties of a Grammatical Marker

10. Sensitivity and Specificity • Sensitivity: rate of identifying true cases of affectedness • Specificity: rate of identifying true cases of unaffectedness

11. Clinical Characteristics of a Grammatical Marker • By a certain age, grammatical markers would show little variation across unaffected children • Affected children would perform below the unaffected children • High levels of sensitivity and specificity • Content would be meaningful for interpretation of a child’s language deficits • Child’s performance would be interpretable in terms of the adult grammar • Markers could persist over time

13. A Finiteness Grammatical Marker • Theoretical Linguistics • Morphology and syntax are related in the area of morphosyntax • Finiteness is a property of clause structure that shows up as verbal forms inflected for tense and/or subject/verb agreement

14. Examples of finiteness markers • Patsy walks home (third person singular subject, present tense) • Patsy walkedhome yesterday (no subject agreement, regular past tense) • Patsy ran home yesterday (no subject agreement, regular past tense) • Patsy is walking (third person singular subject, auxiliary present tense) • Patsy is happy (third person singular subject, copular present tense) • Does Patsy walk home? (third person singular, auxiliary present tense)

15. In English, young children grow into consistent use of finiteness markers, during a period of Optional Infinitives (Wexler, 1994), evident in dropped finiteness markers, thought to be related to the need to mark grammatical tense (TNS).

16. Research with Young Children with SLI • Criteria for SLI in Rice Longitudinal Study • Inclusionary • Expressive language: Low MLU • Receptive language: Low comprehension vocabulary (PPVT) • Low performance on standardized omnibus language test

17. Exclusionary • No hearing loss • Nonverbal IQ in normal range or above • No known neurological or psychosocial problems • Passed a phonological screening

18. Outcomes of Research • SLI children start later, and show slower acquisition timing although similar growth curves

20. Grammatical marker is apparent in judgments as well as productions

22. Young children show variation that disappears by age 5 years, at adult grammar

25. SLI children show variation in a range far below age expectations

27. At the same time of variation as TNS-marking, other elements of morphosyntax are unaffected

30. Lexical indices show consistent variation across the growth curve, and do not differentiate SLI from younger language-equivalent children

33. Timing of acquisition differs for morphosyntactic and morphophonological components of TNS-marking • Past tense variables • Regular (e.g., walked) • Finite (e.g., fell/falled) • Irregular (e.g., fell)

37. Growth curve components and predictors of growth are similar for TNS/finiteness indices, but differ from morphophonological index • TNS productions • Linear and quadratic components for SLI and MLU groups; same curves for both groups • Non-predictors: Intelligence, vocabulary (PPVT-R), mother’s education • Predictor: MLU

38. Grammaticality Judgments: OI Grammar/Bad Agreement Grammar • Linear and quadratic components for SLI and MLU groups; same curves for both groups • Non-predictors: Intelligence, vocabulary (PPVT-R), mother's education • Predictor: MLU

39. Irregular past tense • Linear growth only, for both groups • Non-predictors: Mother's education • Predictors: MLU, vocabulary, intelligence • Finite Past Tense • Linear and quadratic components for SLI and MLU groups; same curves for both groups • Non-predictors: Intelligence, vocabulary, mother's education • Predictor: MLU

40. Conclusions: TNS/AGR marking (finiteness) follows growth curves that are linear + quadratic in shape and growth is not predicted by intelligence, vocabulary or mother's education, and is positively predicted by MLU, although not strongly. When morphophonological accuracy is included in the measurement, the growth curve becomes linear only and the predictors shift to include a child's vocabulary and non-verbal intelligence.

41. Rice/Wexler Test of Early Grammatical Impairment • Advantages compared to other language measures • Focus on finiteness is conceptually sound in terms of the linguistic properties of adult grammar • Performance can be directly interpreted as describing fundamental properties of what a child knows about grammar • Performance can be interpreted in terms of a child's progress toward the adult grammar

42. Content focuses on a property of English grammar that is known to be well mastered by children before they enter school • Focuses on a property of grammar known to be difficult for children with language impairments • Can identify affected children whose sole developmental deficit is language impairment (i.e., SLI)

43. Well suited to identify children of school-entry age who need early intervention • High levels of sensitivity and specificity, leading to accurate identification of affected children, without a high rate of false identification of unaffected children • Includes a screening version

44. General Overview • Consists of five probe tasks and screener: • Phonological • Third person singular • Past tense • BE/DO • Grammaticality judgment • Screener portion is average of third person singular and past tense

45. For children ages 3 to 8 years • Normed to two groups of children per 6-month age interval: Language impaired group and control (normal) group

46. Procedures not usually found in conventional language tests • Phonological probe as screening for test appropriateness • Attention to the syntactic context for morphological assessment • Focus on a morphological class instead of an individual item (e.g., regular verb morphology and class of these verbs instead of a particular lexical item)

47. Differentiation of grammatical functions of a given morpheme (e.g., BE copula vs. auxiliary, questions vs. statements) • Percentage correct of "attempted structures" instead of items correct/total items (i.e., partitioning of off-task or irrelevant items out of scoring) • Calculation of multiple outcomes scores, to form composites and to be considered individually

48. Video demonstration of procedures

49. Tryout and Standardization Sampling Reproduced by Permission. Rice, M. L., & Wexler, K. (2001). Rice/Wexler Test of Early Grammatical Impairment. San Antonio, TX: The Psychology Corporation.

50. Reproduced by Permission. Rice, M. L., & Wexler, K. (2001). Rice/Wexler Test of Early Grammatical Impairment. San Antonio, TX: The Psychology Corporation.