Chapter 20Diagnostic Guidelines Amy Glaspey
Introduction • Purposes of assessment • Establish presence/absence of a disorder • Characterize the nature of the disorder • Document change over time • Document response to treatment • Observe transfer of skills to new contexts (generalization) • This chapter describes • Components of assessment for diagnostic purposes • Assessment during treatment • Video clips: 3-year-old with phonological disorder
Diagnostic Assessment Components of a diagnostic assessment: Client history Standard assessment Dynamic assessment Connected speech sample with phonetic inventory and intelligibility Structural-functional evaluation (with supplemental motor screening) Phonological awareness Hearing screening Supplemental measures
Client History Sidebar 20.1 Sample questions that clinicians may ask a parent or caregiver with a child with suspected speech delay What are your concerns regarding your child’s speech and language? Did any complications occur during pregnancy or birth? Has your child met developmental milestones? When did your child say his/her first words? Has the child experienced any health or medical concerns? Does the child have a history of ear infections? Has the child had a recent hearing screening? How is the child performing in school? How is the child interacting with peers? How well do others understand the child’s speech? Do you have any concerns about academic achievement? Is there a family history of speech, language, or reading problems?
Client History: Cultural Factors Questioning may be perceived as invasive Who is the family spokesperson? Religious beliefs Language proficiency of parent/caregiver
Standard Assessment • Standardized tests come with all materials (pictures, objects) and norms tables • Usually elicit single word productions • Evaluate speech sounds in relevant word positions (initial, medial, final) • Advantages • Target word is known • Comparison to other children of the same age/sex can support decision about treatment • Disadvantages • Lack of ecological validity • Can be misinterpreted; a child’s accuracy on single words may be higher than in conversation • Does not capture small changes • Tests differ in purpose (articulatory accuracy vs. phonological processes). Examples: • Articulation • Goldman-Fristoe Test of Articulation-Second Edition (Goldman & Fristoe, 2000) • Arizona Articulation Proficiency Scale-Third Edition (Fudala, 2000) • Phonological patterns • Hodson Assessment of Phonological Patterns (HAPP) (Hodson, 2004) • Both articulation and phonological patterns • Clinical Assessment of Articulation and Phonology (CAAP) (Secord & Donahue, 2002)
20V1 Standard assessment using the Hodson Assessment of Phonological Patterns
Dynamic Assessment • Measures the type of support needed by the child to produce sounds/patterns successfully • Complementary to standard assessment • Criterion-based (what does this child need to produce the sound/pattern successfully?) • Stimulability • Model – imitation • Sound in syllable • Sound in isolation
Dynamic Assessment cont’d • Adaptability • Scaffolding • Levels of modeling, cueing, prompting • Levels of linguistic complexity
Table 20.2 Glaspey Dynamic Assessment of Phonology (GDAP). A 15-point scale of speech adaptability. Note that a low score is better and shows that the child needs less scaffolding to produce a target.
20V2 Dynamic Assessment. The Glaspey Dynamic Assessment of Phonology (GDAP) • Advantages of dynamic assessment • Helps the clinician gather more detailed information about the child’s abilities and needs • Allows the clinician to track a child’s progress more carefully • Disadvantages of dynamic assessment • Scores may depend on the clinician’s ability to motivate the child and administer the cues • Takes more time • Administering both standardized and dynamic assessment results in a more comprehensive view of the child’s abilities
Connected Speech Sample • Conversation or story from wordless picture book • The clinician listens to the sample and identifies types of errors in the child’s speech • Segmental errors? • Deletions of parts of words? • Only basic syllable shapes? • Connected speech can be analyzed for • Independent phoneme inventory • Relational phoneme inventory
Connected speech can also be used for various accuracy measures (see Chapter 2 for details on how to compute these measures) • Segmental • Percent Consonants Correct • Percent Vowels Correct • Percent Phonemes Correct • Whole word • Syllable shape accuracy • Inventory of syllable shapes • Whole Word Accuracy • Phonological Mean Length of Utterance • Proportion of Whole Word Proximity • Proportion of Whole Word Variability (# different ways a child produced a word/# total times the child produced the word)
Intelligibility • No universally accepted measure of intelligibility exists • Estimate of % intelligible: very subjective • % words glossable: influenced by listener familiarity • Children’s Speech Intelligibility Measure, Wilcox & Morris (1999): Recorded single word imitations judged by an unfamiliar listener • Rating scales • Measure of intelligibility may not be appropriate for severe disorders • Speech samples may be glossed incorrectly • Difficult to measure progress because the child has low intelligibility for a long time • Cannot compare pre/psst data because content of the speech sample cannot be controlled • Solution: collect speech sample from a closed set of words (e.g., wordless picture book) • Collect more than one measure of intelligibility
No noticeable differences from normal. • Intelligible though some differences occasionally noticeable. • Intelligible although noticeably different. • Intelligible with careful listening although some words unintelligible • Speech is difficult to understand with many words unintelligible • Usually is unintelligible. • Unintelligible. • Source: Strand & Skinder (1999)
1. Speech is unintelligible. 2. Speech is usually unintelligible. 3. Speech intelligibility is difficult. 4. Speech is intelligible with careful listening. 5. Speech is intelligible, although noticeably in error. 6. Sound errors are occasionally noticed in continuous speech. (Source: Bauman-Waengler, 2000)
Phonological Awareness • “[A]n awareness of sensitivity to speech sounds and the ability to manipulate the sound structures (i.e., the syllables and phonemes) in words” (Hart Paulson & Moats, 2010 p. 52) • Deficits put children at risk for problems with written language later • Phonological processing skills include • Rhyming • Alliteration • Blending • Segmenting • Nonword repetition
Structural-Functional Examination • Structures: symmetry, anomalies • Lips • Teeth • Mandible/maxilla • Hard/soft palate/uvula • Pharynx • Tonsils • Function • Lips • Tongue • Palate • Diadochokinetics
Hearing Screen • Pure tones at 20 dB SLP • .5, 1, 2, 4 KHz • Why? • The role of otitis media with effusion in the development of speech is unclear • Impaired hearing at age 18 to 21 months resulted in a 10 to 21 fold risk increase for speech disorder later (Shriberg, Friel-Patti, Flipsen, & Brown, 2000)
Supplemental Assessment • If the child presents with unusual speech production difficulties, it may be necessary to obtain supplemental measures. Some examples are: • If motor speech difficulties are suspected, the motor system should be evaluated further, e.g., to test for apraxia of speech • If the clinician suspects that the language system is impaired, receptive and especially expressive language abilities should be tested.
Completing the Evaluation and Making a Diagnosis • A comprehensive set of data has been collected. Next step: Diagnosis • Does the child have a speech sound disorder or not? • If yes: differential diagnosis • Consider all potential candidates • Select the candidate that best fits the child’s profile • Articulation (consistently misarticulated) errors • Phonological (pattern-based) errors • Or both • If phonological errors: • Delay or disorder? • Consistent or inconsistent? • From supplemental testing • Motor-based speech disorder • Receptive and/or expressive language • How severe is the disorder? • What effect does the disorder have on the child’s daily life?
From Diagnosis to Treatment • No intervention necessary • The data show that the child’s speech is within normal limits for age and sex • The data show that the child’s speech errors are slightly delayed compared to typically developing children • Intervention recommended • There is a moderate to severe delay • There is evidence that the child’s speech is not following typical trajectories and most likely will not self-correct • The clinical context • Depending on available resources, the SLP must show • Standard scores lower than 1.5 SD below the mean (or lower) • A certain number of speech sounds across classes must be in error • Next step: selecting a treatment approach that has been shown to be effective and that is appropriate for the type of speech disorder described in the assessment
Connections This chapter: Process of gathering and interpreting information when a child is referred for an initial evaluation because of concerns regarding her or his speech production Chapter 2: Detailed overview of tools for describing and measuring children’s speech abilities for clinical as well as research purposes Chapters 4, 5, and 6: Various aspects of speech development in typically developing, English-speaking children, providing a reference against which to compare disordered development Chapter 7: Acquisition of prosody and ways to assess it. Chapter 22: Pathway from diagnosis to treatment selection, design, and implementation; also: use of assessment throughout treatment to document progress and probe for generalization
Concluding Remarks • Assessment is also a regular component of treatment to track • Daily/weekly progress • Generalization probes