Do vocabulary skills in infancy predict reading and language skills

in later childhood?

Fiona DuffGurpreet Reen, Kim Plunkett, Kate Nation

Language for Reading

decoding × linguistic comprehension = reading comprehension

nonphonological language Clarke et al. (2010)

phonological language Hulme et al. (2012)

Language for Reading

decoding × linguistic comprehension = reading comprehension

nonphonological language Clarke et al. (2010)

phonological language Hulme et al. (2012)

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

Measuring Vocabulary

Comprehension Production

319

127

200

16

• Oxford Communicative Development Inventory– Parental checklist of infants’ knowledge of 416 words– Standardised on 669 British infants (Hamilton et al., 2000)

Participants in Infancy

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

Participants at School-Age

• 300 children in ≈150 schools

Year N Age (SD)

Reception 75 5;02 (0;04)Year 1 55 6;00 (0;05)Year 2 85 6;11 (0;05)Year 3 66 8;00 (0;05)Year 4 19 9;00 (0;03)

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)

Participants at School-Age

School-Age Measures

N Mean SD Min MaxReceptive vocab 298 88.49 17.57 35 135Expressive vocab 300 79.77 17.78 30 122Phonological deletion 298 9.74 5.21 0 20Nonword reading 300 14.76 8.81 0 30Regular word reading 300 18.42 9.63 0 30Exception word reading 300 15.21 10.13 0 30Word reading accuracy 300 48.39 27.73 0 90Prose reading accuracy 225 48.54 12.13 4 77Reading comprehension 226 57.97 11.63 9 79Nonverbal IQ 298 79.42 22.64 18 135

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

Infant vocabulary

Comprehension Production

.72 .79

Vocabulary

Receptive Expressive

.73 .84

Phonological awareness

Reading accuracy

Nonwords Regulars Exceptions

.86 .97 .93

Reading comprehension

Passage 1 Passage 2

.79 .78

.29

.56

.81

.49

.38

.81

Infant vocabulary

Comprehension Production

.72 .79

Vocabulary

Receptive Expressive

.73 .84

Phonological awareness

Reading accuracy

Nonwords Regulars Exceptions

.86 .97 .93

Reading comprehension

Passage 1 Passage 2

.79 .78

.29

.56

.81

.49

.38

.81

Infant vocabulary

Comprehension Production

.72 .79 .40

.21

.33

.43

Vocabulary

Receptive Expressive

.73 .84

Phonological awareness

Reading accuracy

Nonwords Regulars Exceptions

.86 .97 .93

Reading comprehension

Passage 1 Passage 2

.79 .78

.29

.56

.81

.49

.38

.81

Infant vocabulary

Comprehension Production

.72 .79 .40

.21

.33

.43

Vocabulary

Receptive Expressive

.73 .84

.84

Phonological awareness

.96

Reading accuracy

Nonwords Regulars Exceptions

.86 .97 .93

.89

Reading comprehension

Passage 1 Passage 2

.79 .78

.82

N = 300Chi-square test of model fit:χ2 (26) = 44.87 p = .012CF1 = .989; RMSEA = .049

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)

Family-Risk

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

Reading Risk: No

Reading Risk: Yes

Totals

Language Risk: No

98 29 125

Language Risk: Yes

9 5 14

Totals 105 34 139

.28

.55

.78

.49

.36

.84

Family risk

Infant vocabulary

Comprehension Production

.71 .79

-.16

.38

.18

.28

.38

-.09

-.15

-.32

-.34

Vocabulary

Receptive Expressive

.74 .83

.84

Phonological awareness

.94

Reading accuracy

Nonwords Regulars Exceptions

.86 .97 .93

.79

Reading comprehension

Passage 1 Passage 2

.79 .77

.70

N = 300Chi-square test of model fit:χ2 (31) = 48.58, p = .023CF1 = .989; RMSEA = .043

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%)

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

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