Cross-Battery Assessment: Step-by-Step

Transcription

1 Cross-Battery Assessment: Step-by-Step MASP, AGM 2013 Jen Theule, Ph.D., C. Psych. University of Manitoba Overview of Cattell-Horn-Carroll (CHC) Theory of Cognitive Abilities 3 strata theory of intelligence Stratum III: g (Spearman) Stratum II: broad abilities (now 16), including Gf and Gc Stratum I: narrow abilities (now 80) Strata differ in degree of generality CHC Theory CHC Comprehensive and empirically-supported (e.g., factor analytic, neurobiological) Hierarchical Psychometric theory (structure of intelligence can be understood by analyzing scores on mental ability tests) g: Involved in complex higher-order cognitive processes Fluid intelligence: nonverbal, culture free, mental efficiency Crystallized intelligence: acquired skills and knowledge Updated CHC Theory (Schneider & McGrew, 2012) Narrow Abilities Stratum II Broad Abilities: now 16 (was 10) Grouped into 6 conceptual categories: 1. Reasoning: Gf, Gc 2. Acquired Knowledge: Gc, Gkn, Gq, Grw 3. Memory and Efficiency: Gsm, Glr 4. Sensory: Gv, Ga, Go, Gh 5. Motor: Gp, Gk 6. Speed and Efficiency: Gs, Gt, Gps Correspond to operational definitions of cognitive processes 1

2 Cross-Battery Assessment (XBA) Crossing Batteries Based on CHC model Developed by Flanagan, McGrew, & Ortiz Measure a wider range of abilities than represented by a single intelligence test think outside the test kit Neuropsychology We all do cross-battery assessment already! XBA More psychometrically and theoretically defensible method of crossing batteries Still some concerns and limitations (see crossbattery.com) When is XBA indicated? Learning questions Learning Disabilities Slow Learner ADHD Processing questions Neuropsychological questions Nonverbal learning disabilities Neuropsych disorders (e.g., William s, Fragile X) Culturally/linguistically diverse Limitations of CHC and XBA What do I need to measure? Data focus leads to circular arguments Data focus limits ideas about intelligence to what is measured Can provide more data than needed: can you see the forest for the trees Usually measure these broad abilities in a typical assessment: Gc, Gf, Gv, Gsm, Ga, Glr, Gs At least 2 qualitatively different subtests (indicators) to measure each broad ability (and must hang together usually <15 SS points difference) To measure a narrow ability also usually need 2 subtests 2

3 What should I try to avoid measuring? XBA Tools Construct irrelevant variance: adds in unneeded information E.g., fine-motor or mixes 2 abilities at the level of your investigation E.g., VIQ: measures Gc and Gsm E.g., verbal analogies measures Gc and Gf You can base your assessment on just about any battery! Some batteries are easier as they are based on CHC: WJ-III, K-ABC-II, SB-5, DAS Regardless of battery you will likely need to supplement ( cross-batteries ), but less if use one designed around CHC Because: most tests don t measure the range of broad cognitive abilities XBA and Test Choice What does a Cross-Battery Assessment look like? Choose: 1. Same battery (e.g., all K-ABC) 2. Co-normed tests (e.g., WISC-IV and WIAT-III OR WJ COG and ACH) 3. Tests normed within a few years of each other (Flynn Effect) 4. Other subtests Try to use the lowest number of batteries possible. Test 7 broad areas (see earlier) Test other areas as indicated by hypotheses Follow-up on strengths and weaknesses Follow-up on inconsistencies Check for ecological validity Check potential recommendations (dynamic assessment) WJ- III Correla2ons with WISC Specific Learning Disability Identification and XBA WISC- IV FSIQ is lower than WJ- III GIA- Ext in children with neuropsychiatric disorders WJ III GIA (general intellectual ability) measures were compared against other intelligence tests: - WISC III-.71 for GIA- Std and.76 for GIA- Ext Difficulties in one or more areas of academic achievement Not the result of visual, hearing, environmental, etc. variables Disorder in basic psychological process involved in reading, writing, etc. Unexpected underachievement Ecologically valid Conditions: Average or better cognitive abilities 3

4 Operational Definition of SLD Cross-Battery and LDs Narrow abilities somewhat remediable. Discrepant Discrepant Narrow ability weaknesses can be appropriately accommodated (see Essentials book) Consisten t Referral History 10-year-old girl, Grade 4 Functioning at approximately a Grade 2 level in all areas Limited understanding of numbers Trouble generating ideas for writing Reading is weak Gets distracted at times, some organizational difficulties Good persistence Premature birth (34 weeks) Parents divorced, father remarried, adopted by stepmother First words 15 months old Walked 10 months Articulation difficulties as preschooler, saw SLP Family history: depression, ADHD, learning difficulties Enjoys building things Has friends, but history of minor bullying Hypotheses What areas do we need to assess? Global Delays (intellectual disability, slow learner) Learning Disability Overall estimate of ability 7 stratum II areas: Gc, Gf, Gv, Gsm, Ga, Glr, Gs Language Disorder ADHD 4

5 Need to assess: Reading Need to assess: Math Ga: Phonetic coding (PC) Gc: Lexical knowledge (VL) Listening ability (LS) Language development General information (K0) Gsm: Memory span (MS) Glr: Naming facility (NA) Gs: Perceptual speed (P) Gf: Inductive (I) General sequential reasoning (RG) Gc: Lexical knowledge (VL) Listening ability (LS) Language development Gsm: Memory span (MS) Gs: Perceptual speed (P) Need to assess: Writing Need to assess: Language Gc: Lexical knowledge (VL) Language development General information (K0) Gsm: Memory span (MS) Working memory capacity (MW) Ga: Phonetic coding (PC) Gs: Perceptual speed (P) Language is part of cognition Gc: Crystallized intelligence. The depth and breadth of knowledge and skills that are valued by one s culture. Conduct comprehensive evaluation of Gc Need to assess: ADHD Gsm Gs Executive functioning How do I figure out what to assess? 1. Start with your hypotheses 2. Make a chart of what you would ideally assess 3. Based on examinee characteristics and best practices (see above) choose a core battery 4. Look for overlap in assessment list start there 5. Assess 7 broad areas 6. Consider results, add/subtract subtests from list. Repeat. Iterative Process 5

6 Bringing it together Based on WISC-IV Overall estimate of ability 7 stratum II areas: Gc, Gf, Gv, Gsm, Ga, Glr, Gs Given referral and overlap: Gc: Lexical knowledge (VL), language development Gsm: Memory span (MS) Gs: Perceptual speed (P) FSIQ and most broad areas: Core 10 subtests (BD, SI, DS, PCn, Co, VC, LN, MR, Co, SS) Gv: PCm P (Gs): Cancellation Outside of battery: LD (Gc): TOLD Word Ordering, Sentence Combining Gf: WJ Analysis-Synthesis (RG) Ga: WJ Sound Blending (PC) and Auditory Attention (UR) Glr: WJ Visual-Auditory Learning (MA) and Retrieval Fluency (FI) Do I have to do all of that? Based on WJ-III NU No. If first test of narrow ability is average or better don t need a second. If first test of narrow ability is weak can skip second test if have other data source (ecological validity) supporting weakness (less likely) GIA: first 7 subtests Gf: Analysis-Synthesis Gc: General Information Gv: Picture Recognition Gsm: Memory for Words Glr: Rapid Picture Naming Ga: Auditory Attention Gs (P): Decision Speed Outside of battery: Gs: WISC Coding LD (Gc): TOLD Word Ordering, Sentence Combining VL (Gc): WISC Vocabulary MS (Gsm): WISC Digit Span Achievement Results Note: Ability and achievement not considered different in XBA!! Will be different based on WJ or WISC Re-evaluate as needed, and add, subtract from your plan Do appropriate academic testing to pinpoint level of academic functioning, using co-normed tests if possible. 6

7 Results Continued What next? Examples: Gc weak want to follow up with more narrow abilities to pinpoint. Symbol Search (Perceptual speed = P)- ss of 13 no need to test P further with Cancellation Gv not cohesive, Block Design = 4 (Vz), Picture Completion = 8 (CF). Test Vz and CF more, and possibly another Gv area Reading Comprehension: SS = 105 lacks ecological validity Follow up on strengths and weaknesses Inconsistencies Lack of ecological validity Revisit hypotheses and revise plan Check potential recommendations (dynamic) Formulation Recommendations Language Disorder Provide language-enriched environment Read aloud to kids Recursive process: Consider testing through lens of culture-language matrix! Reconsider: Letter-Number Sequencing (WISC), Analysis-Synthesis (WJ), Auditory Attention (WJ), Concept Formation (WJ), Decision Speed (WJ), Memory for Words (WJ) Books on tape Speech-language therapy Use diagrams, etc. for teaching Resources Questions? 7