Do vocabulary skills in infancy predict reading and language skills in later childhood?

1. Do vocabulary skills in infancy predict reading and language skills in later childhood? Fiona Duff GurpreetReen, Kim Plunkett, Kate Nation

2. Language for Reading decoding × linguistic comprehension = reading comprehension nonphonological language Clarke et al. (2010) phonological language Hulme et al. (2012)

3. Language for Reading decoding × linguistic comprehension = reading comprehension nonphonological language Clarke et al. (2010) phonological language Hulme et al. (2012)

4. Research Questions • If vocabulary predicts reading, vocabulary deficits signal risk of later reading difficulties • Is there a relationship between infant vocabulary and later literacy? • Could infant vocabulary deficits be used to identify children at risk of reading difficulties? Infant vocabulary School-age language/ literacy

5. Measuring Vocabulary • Oxford Communicative Development Inventory • Parental checklist of infants’ knowledge of 416 words • Standardised on 669 British infants (Hamilton et al., 2000) Comprehension Production 319 200 127 16

6. Participants in Infancy Correlation between CDIs at t1 and t2 (n=100): Comp. = .75, Prod. = .70 (p < .001)

7. Participants at School-Age • 300 children in ≈150 schools

8. School-Age Test Battery • Language • Receptive vocabulary (ROWPVT) • Expressive vocabulary (EOWPVT) • Phonological deletion (CTOPP Elision) • Reading • Reading accuracy (DTWRP) • Reading comprehension (YARC) • General cognitive ability • Nonverbal reasoning (BAS-II Matrices)

9. Participants at School-Age

10. School-Age Measures

11. Research Questions • If vocabulary predicts reading, vocabulary deficits signal risk of later reading difficulties • Is there a relationship between infant vocabulary and later literacy? Infant vocabulary School-age language/ literacy

12. Receptive Expressive .84 .73 Vocabulary Comprehension Production .79 .72 Infant vocabulary Phonological awareness Nonwords Regulars Exceptions .93 .97 .86 Reading accuracy Passage 1 Passage 2 .78 .79 Reading comprehension

13. Receptive Expressive .84 .73 Vocabulary Comprehension Production .79 .72 .29 Infant vocabulary Phonological awareness .49 Nonwords Regulars Exceptions .81 .56 .93 .97 .86 Reading accuracy .38 .81 Passage 1 Passage 2 .78 .79 Reading comprehension

14. Receptive Expressive .84 .73 Vocabulary Comprehension Production .79 .72 .29 .40 Infant vocabulary Phonological awareness .21 .49 .33 Nonwords Regulars Exceptions .43 .81 .56 .93 .97 .86 Reading accuracy .38 .81 Passage 1 Passage 2 .78 .79 Reading comprehension

15. Receptive Expressive .84 .73 Vocabulary Comprehension Production .84 .79 .72 .29 .40 Infant vocabulary Phonological awareness .21 .49 .33 .96 Nonwords Regulars Exceptions .43 .81 .56 .93 .97 .86 Reading accuracy .38 .89 .81 Passage 1 Passage 2 .78 .79 N = 300 Chi-square test of model fit: χ2 (26) = 44.87 p = .012 CF1 = .989; RMSEA = .049 Reading comprehension .82

16. Interim Summary • Infant vocabulary is a significant predictor of school-age outcomes, accounting for: • 4% variance in phoneme awareness • 11% variance in reading accuracy • 16% variance in vocabulary • 18% variance in reading comprehension • However, it is not a sufficient predictor • What else can explain the remaining variance? • Family-risk: a better predictor of language outcomes at 4 years than ‘late talker’ status at 18 months (Bishop et al., 2012)

17. Family-Risk • Family-risk (FR) questionnaire • First degree relative with a reading or language difficulty

18. Receptive Expressive .83 .74 Vocabulary Comprehension Production .84 -.09 .79 .71 .28 .38 Infant vocabulary Phonological awareness .18 .49 .28 -.15 .94 Nonwords Regulars Exceptions .38 -.16 .84 .55 .93 .97 .86 Reading accuracy Family risk -.32 .36 .79 .78 Passage 1 Passage 2 .77 .79 -.34 N = 300 Chi-square test of model fit: χ2 (31) = 48.58, p = .023 CF1 = .989; RMSEA = .043 Reading comprehension .70

19. Conclusions and Implications • Infant vocabulary is a significant but not sufficient predictor of later reading and language outcomes • Family-risk explains additional variance in reading but not language outcomes • The two predictors explain: • 6% variance in phoneme awareness (cf. 4%) • 16% variance in vocabulary (cf. 16%) • 21% variance in reading accuracy (cf. 11%) • 30% variance in reading comprehension (cf. 18%)

20. Conclusions and Implications • Caution against using parent report of vocabulary as sole predictor of outcomes, especially for language: • Low stability of vocabulary from pre-24 months to school-age • Around 70% of 18-month-old ‘late talkers’ resolve (Bishop et al., 2012) • Prediction of reading risk increased if consider infant vocabulary with family history • Future research needs to address: • What FR is tapping • Whether prediction is improved when language is measured later on, more comprehensively, or more objectively

21. Acknowledgements • Julia Dilnot, University of Cambridge • Jane Ralph, University of Oxford • Dr Suzy Styles, Technical University, Singapore • Professor Dorothy Bishop, University of Oxford • Professor Charles Hulme, UCL • Schools, families and children