Application of optimal sign-vectors to reliability and cluster analysis

Expressions involving optimal sign vectors are derived so as to yield two new applications. First, coefficient alpha for the sign-weighted composite is maximized in analogy to Lord's scale-independent solution with differential weights. Second, optimal sign vectors are used to define two groups of objects that are maximally distinct in terms of a function of the squared euclidean distances between groups. An efficient computing algorithm is described along with several examples.This research was supported in part by a research grant (DA 01070) from the U. S. Public Health Service.     

Inequalities among lower bounds to reliability: With applications to test construction and factor analysis

A chain of lower-bound inequalities leading to the greatest lower bound to reliability is established for the internal consistency of a composite of unit-weighted components. The chain includes the maximum split-half coefficient, the lowest coefficient consistent with nonimaginary common factors, and the lowest coefficient consistent with nonimaginary common and unique factors. Optimization theory is utilized to determine the conditions that are requisite for the inequalities. Convergence proofs demonstrate that the coefficients can be attained. Rapid algorithms obtain estimates of the coefficients with sample data. The theory yields methods for splitting items into maximally similar sets and for exploratory factor analysis based on a theoretical solution to the communality problem.     

Four‐model approach to adolescent–parent attachment relationships and adolescents' loneliness,school belonging,and teacher appraisal

This study tested monotropy, hierarchy, independence, and integration conceptual models of adolescent–mother and adolescent–father attachment to explain adolescents' perceived social interrelationships with extrafamilial attachment figures (peers, teachers). Participants included 356 Israeli adolescents (12–15 years). More adolescents were significantly classified as securely attached to mothers than to fathers, but high concordances emerged. Results supported two of the attachment models, hierarchy and integration, as explaining variation in adolescents' perceived extrafamilial interrelationships. As per the hierarchy attachment model, adolescent–mother attachment outweighed adolescent–father attachment to some extent in predicting adolescents' perceived social interrelationship measures. As per the integration attachment model, significant differences emerged on most social interrelationship measures between the 4 distinct subgroups: secure attachment to both parents, neither, only father, only mother. The Discussion section focuses on the unique importance of attachment to each parent for typically developing junior high students.     

Not all emotions are created equal: the negativity bias in social-emotional development

There is ample empirical evidence for an asymmetry in the way that adults use positive versus negative information to make sense of their world; specifically, across an array of psychological situations and tasks, adults display a negativity bias, or the propensity to attend to, learn from, and use negative information far more than positive information. This bias is argued to serve critical evolutionarily adaptive functions, but its developmental presence and ontogenetic emergence have never been seriously considered. The authors argue for the existence of the negativity bias in early development and that it is evident especially in research on infant social referencing but also in other developmental domains. They discuss ontogenetic mechanisms underlying the emergence of this bias and explore not only its evolutionary but also its developmental functions and consequences. Throughout, the authors suggest ways to further examine the negativity bias in infants and older children, and they make testable predictions that would help clarify the nature of the negativity bias during early development.     

Pulling out the intentional structure of action: the relation between action processing and action production in infancy

Adults and children readily construct action representations organized with respect to an ultimate goal. These representations allow one to predict the consequences of action, interpret and describe actions, and categorize action sequences. In this paper, we explore the ontogeny of hierarchically organized action representations, and its relation to infants' ability to produce similar sequences. To do so, we examine infants' perception and performance of a means-end sequence: pulling a cloth to retrieve a toy. Using a visual habituation paradigm, we demonstrate that 12-month-old infants understand that the initial step of the cloth-pulling sequence is directed toward the ultimate goal of attaining the toy, and use their knowledge of the causal constraints of the sequence to make this goal attribution. Ten-month-olds, however, appear transitional with respect to this understanding: their ability to identify the goal of the cloth-pulling sequence is related to their own ability to planfully solve a similar sequence. These findings are consistent with a burgeoning body of literature suggesting an intimate link between action production and perception, and suggest that this link is in place by at least 10 months of age.     

Factors associated with loneliness among alcoholics in rehabilitation centers.

Loneliness questionnaires were distributed to 92 male and 60 female American subjects undergoing treatment in selected alcohol rehabilitation centers. Factors associated with feelings of loneliness for these individuals were investigated. Significant differences were found between the loneliness scores of men and women, between individuals who had different familial histories of alcoholism, and between subjects who indicated various degrees of happiness during the previous year. A significant negative relationship was also found between loneliness and the following variables: self-esteem, self-rated marital satisfaction, self-rated job satisfaction, and number of years alcohol was consumed.     

Ethical considerations in the testing of biopharmaceuticals for adventitious agents

Safety testing of biological pharmaceuticals is often carried out by contract testing laboratories which perform these tests on behalf of the drug’s developer. These laboratories are confronted with a number of ethical issues related to selling their services, maintaining confidentiality, and the handling of results. This paper outlines these issues, and, by way of illustration, discusses how one such laboratory addresses them.