Normative developmental trajectories of actigraphic sleep variables during the preschool period: A three‐wave longitudinal study
Bibliographic record
Abstract
Important changes in sleep are believed to occur in the preschool years, but studies that have documented these changes were generally cross-sectional or based on subjective sleep measures. The current longitudinal study modeled the developmental trajectories followed by five sleep variables objectively assessed during the preschool period. Children (N = 128) wore an actigraph over 3 days at 2, 3, and 4 years of age and change in sleep variables was assessed with growth curves. The results showed a linear decrease of daytime, total, and nighttime sleep duration, and a linear increase of sleep efficiency and proportion of nighttime to total sleep. For all sleep variables, the rhythm of change was relatively uniform across children, but there was significant inter-individual variation around the initial status for most variables. To our knowledge, this study is the first to model the developmental trajectories followed by several sleep variables during the preschool period.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".