Summary statistics of the WebCDI sample of CDI-III data (English and Spanish) from Virginia.

Adding Philip’s data.

English Demographics

We have item-level data from 234 participants, and summary data from a further 499 participants from the 2007 CDI-III norms. Vocabulary totals from all participants are shown below, but the targeted age range (30-37 months) is highlighted.

437 participants fall in the 30-37 month age range.

Age breakdown:

Mother education breakdown:

Mother education for 30-37 month-olds:

Total Vocab by age group for 30-37 month-olds:

Sex breakdown:

English summary plot

Quantile Plots and Tables

Figure 6.1. Growth in vocabulary scores for girls. (Note: These scores should not be interpreted as the child’s total vocabulary, as only a small sample of words occur on the CDI-III.)

Figure 6.2. Growth in vocabulary scores for boys. (Note: These scores should not be interpreted as the child’s total vocabulary, as only a small sample of words occur on the CDI-III.)

# tables show # of words known by age / percentile 
# columns: %ile rank, Age: 30–31    32–33   34–35   36–37
pctile = c(seq(5,95, 5), 99)

Table 6.2. The MacArthur-Bates Communicative Development Inventory–III (CDI-III) fitted percentile values for Vocabulary Checklist—both sexes combined

Table 6.3. The MacArthur-Bates Communicative Development Inventory–III (CDI-III) fitted percentile values for Vocabulary Checklist—girls

Table 6.4. The MacArthur-Bates Communicative Development Inventory–III (CDI-III) fitted percentile values for Vocabulary Checklist—boys

Percentile Tables: Sentences

Table 6.5. The MacArthur-Bates Communicative Development Inventory–III (CDI-III) fitted percentile values for Sentences—both sexes combined

Table 6.6. The MacArthur-Bates Communicative Development Inventory–III (CDI-III) fitted percentile values for Sentences—girls

Table 6.7. The MacArthur-Bates Communicative Development Inventory–III (CDI-III) fitted percentile values for Sentences—boys

Percentile Tables: Using Language

Table 6.8. The MacArthur-Bates Communicative Development Inventory–III (CDI-III) fitted percentile values for Using Language—both sexes combined

Table 6.9. The MacArthur-Bates Communicative Development Inventory–III (CDI-III) fitted percentile values for Using Language—girls

Table 6.10. The MacArthur-Bates Communicative Development Inventory–III (CDI-III) fitted percentile values for Using Language—boys

Spanish Demographics

We have a total of 562 Spanish participants.

ggplot(sp_demo, aes(x = Age, y = TotalVocab, color=Sex)) + 
  geom_jitter(alpha = .5) + geom_smooth(method=lm, formula=y ~ poly(x,2)) +
  theme_bw() + xlab("Age (months)") + ylab("Total Vocabulary")

Age breakdown:

Mother education breakdown:

Mother education for 30-37 month-olds:

Total Vocab by age group for 30-37 month-olds:

Sex breakdown:

Spanish summary plot