Table 1.
Mean values, stability, and continuity for measures of language production and conversational discourse.
| Variable | Mean |
Stability |
Continuity |
|||
|---|---|---|---|---|---|---|
| Visit 1 | Visit 2 | r | p | d z | p | |
| Child language production | ||||||
| MLU in words | 1.57 | 2.01 | .38 | < .001 | 0.91 | < .001 |
| NDW (10 min adjusted) | 36 | 54 | .57 | < .001 | 0.83 | < .001 |
| Mother language production | ||||||
| MLU in words | 3.45 | 3.42 | .52 | < .001 | −0.04 | .67 |
| NDW (10 min adjusted) | 100 | 131 | .69 | < .001 | 0.94 | < .001 |
| Child discourse | ||||||
| MTL in utterances | 1.16 | 1.26 | .50 | < .001 | 0.59 | < .001 |
| Question rate (per 10 min) | 9.9 | 11.4 | .29 | < .001 | 0.14 | .13 |
| Response percentage | 52 | 59 | .31 | < .001 | 0.38 | < .001 |
| Mother discourse | ||||||
| MTL in utterances | 2.94 | 2.56 | .33 | < .001 | −0.31 | .001 |
| Question rate (per 10 min) | 56 | 38 | .61 | < .001 | −0.90 | < .001 |
| Response percentage | 92 | 87 | .14 | .14 | −0.31 | .001 |
Note. MLU = mean length of utterance; NDW = number of different words; MTL = mean turn length; d z = standardized mean difference. N = 119 except 115 and 116 for mother response percentage at Visits 1 and 2, respectively. Children's mean ages at Visits 1 and 2 were 2.5 and 3.6 years, respectively.