Children's fuzziness leads to increased variance in the data, data loss, and high dropout rates in developmental studies. This study investigated the importance of 20 factors on the person (child, caregiver, experimenter) and situation (task, method, time, and date) level for the data quality as indicated via the number of valid trials in 11…

This study of the stability of parent behaviors toward toddlers over a 3-week period used both aggregated and nonaggregated data. Comparison of stability correlations indicated higher stabilities for aggregated scores, with the level of stability increasing as scores from additional single sessions were aggregated. (PCB)

Examines difficulties associated with the use of conversational features in the analysis of mother-infant vocalization episodes. Observations of six mother-infant dyads revealed difficulties involving (1) pooling of data; (2) the unit of analysis; and (3) selection of appropriate "expected" values for dyadic parameters used in tests of…

This study reports various aspects of the analyses carried out on the longitudinal data reported in a previous study (PS 007 345) for determining the general growth patterns and growth velocity of mental and motor development. Preliminary analyses focused on the selection of the growth curve, its evaluation in the 208 individual cases, and the…

This paper discusses a longitudinal, exploratory study of developmental dimensions related to object permanence theory and explains how multidimensional scaling techniques can be used to identify developmental dimensions. Eighty infants, randomly assigned to one of four experimental groups and one of four counterbalanced orders of stimuli, were…