Table 1. Characteristics of each child in the classroom.
| Child | Sex | Overall annual classroom attendance rate | Number of recordings | Age at enrollment (months) | Time 1 vocabulary | Time 2 vocabulary | Time 3 vocabulary |
|---|---|---|---|---|---|---|---|
| 1 | female | .61 | 9 | 26 | 11 | 315 | no longer enrolled |
| 2 | male | .38 | 8 | 28 | 50 | 261 | no longer enrolled |
| 3* | female | .09 | 1 | 23 | 48 | no longer enrolled | no longer enrolled |
| 4 | female | .93 | 18 | 24 | 1 | 87 | 108 |
| 5 | female | .64 | 17 | 21 | 83 | 399 | 429 |
| 6 | male | .55 | 13 | 26 | 24 | 303 | 435 |
| 7 | female | .56 | 17 | 30 | 78 | 318 | 457 |
| 8 | female | .50 | 10 | 23 | 24 | 233 | 415 |
| 9 | female | .83 | 22 | 28 | 180 | 498 | 475 |
| 10 | female | .47 | 10 | 22 | 29 | 91 | 427 |
| 11 | male | .13 | 7 | 24 | 15 | 74 | 119 |
| 12 | female | .15 | 5 | 30** | not yet enrolled | 382 | 431 |
| 13 | male | .45 | 16 | 28** | not yet enrolled | 5 | 11 |
| 14 | female | .28 | 13 | 36** | not yet enrolled | 412 | 430 |
| 15* | female | .05 | 1 | 32*** | not yet enrolled | not yet enrolled | 286 |
Notes. Time 1 expressive vocabulary size was measured 1 month prior to study initiation; Time 2 expressive vocabulary size was measured 6 months into the study; and Time 3 expressive vocabulary size was measured 1 month after study completion.
*child contributed too few recordings and was not included as a participant.
**child was enrolled 6–8 months after study initiation.
***child was enrolled 11 months after study initiation.