Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network

  Advanced Search  

What Is the Shape of Developmental Change? Karen E. Adolph

Summary: What Is the Shape of Developmental Change?
Karen E. Adolph
New York University
Scott R. Robinson
University of Iowa
Jesse W. Young
Stony Brook University
Felix Gill-Alvarez
New York University
Developmental trajectories provide the empirical foundation for theories about change processes during develop-
ment. 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 (231 days) were simulated by system-
atically 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


Source: Adolph, Karen - Center for Neural Science & Department of Psychology, New York University
Robinson, Scott R. - Department of Psychology, University of Iowa


Collections: Biology and Medicine