ERIC Number: EJ823647
Record Type: Journal
Publication Date: 2008-Jul
Abstractor: As Provided
Reference Count: 0
What Is the Shape of Developmental Change?
Adolph, Karen E.; Robinson, Scott R.; Young, Jesse W.; Gill-Alvarez, Felix
Psychological Review, v115 n3 p527-543 Jul 2008
Developmental trajectories provide the empirical foundation for theories about change processes during development. However, the ability to distinguish among alternative trajectories depends on how frequently observations are sampled. This study used real behavioral data, with real patterns of variability, to examine the effects of sampling at different intervals on characterization of the underlying trajectory. Data were derived from a set of 32 infant motor skills indexed daily during the first 18 months. Larger sampling intervals (2-31 days) were simulated by systematically removing observations from the daily data and interpolating over the gaps. Infrequent sampling caused decreasing sensitivity to fluctuations in the daily data: Variable trajectories erroneously appeared as step functions, and estimates of onset ages were increasingly off target. Sensitivity to variation decreased as an inverse power function of sampling interval, resulting in severe degradation of the trajectory with intervals longer than 7 days. These findings suggest that sampling rates typically used by developmental researchers may be inadequate to accurately depict patterns of variability and the shape of developmental change. Inadequate sampling regimes therefore may seriously compromise theories of development.
Descriptors: Intervals, Child Development, Sampling, Infant Behavior, Infants, Theories, Developmental Psychology, Developmental Stages, Research Methodology, Research Problems, Trend Analysis, Longitudinal Studies
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Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Authoring Institution: N/A