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This article illustrates the use of latent transition analysis (LTA), a methodology for testing stage-sequential models of individual growth. LTA is an outgrowth of latent class theory and is a particular type of latent Markov model emphasizing the use of multiple manifest indicators. LTA is used to compare the fit of two models of early adolescent(More)
Evaluations of psychological interventions are often criticized because of differential attrition, which is cited as a severe threat to validity. The present study shows that differential attrition is not a problem unless the mechanism causing the attrition is inaccessible (unavailable for analysis). With a simulation study, we show that conclusions about(More)
Outcome research has shown that drug prevention programs based on theories of social influence often prevent the onset of adolescent drug use. However, little is known empirically about the processes through which they have their effects. The purpose of the present study was to evaluate intervening mechanism theories of two program models for preventing the(More)
Social influence is central to models of adolescent substance use. Nonetheless, researchers fail to delineate the various forms of social influence. A framework that distinguishes between active (explicit drug offers) and passive (social modeling and overestimation of friends' use) social pressure was tested. The effect of these processes on alcohol and(More)
In this study, the authors compared group members' and group outsiders' susceptibility to the influence of their friends' smoking. Ss were nonsmokers in Grade 7 who were observed for 1 year. Consistent with their hypothesis, the authors found that group outsiders (Ss who did not have reciprocal friends) were affected more by the smoking of their best friend(More)
Patients newly diagnosed with hematologic malignancies were followed for a 6-month treatment period to assess compliance with three regimen requirements for cancer therapy: anti-neoplastic medication self-administered intermittently, supportive medication self-administered daily, and monthly clinic appointments. The effect on compliance of three(More)
The purpose of this study was to determine the degree to which the use of tobacco, alcohol, and marijuana by young adolescents can be described using a common theoretical model. Structural models were created in which psychosocial variables hierarchically predicted the use of each substance. The fit of a model in which paths from predictor variables were(More)
Although previous studies have suggested the inadequacy of the two-factor models of positive and negative symptoms in schizophrenia, confirmatory testing of the putative three-factor models is needed. Using a sample of 193 individuals diagnosed with schizophrenia, this study tested the relative goodness-of-fit of one-, two-, and three-factor models of the(More)
We examined the effects of health locus of control beliefs (self-, doctor, and chance control) and expectations of treatment efficacy on short-term psychological adjustment in a sample of newly diagnosed cancer patients. The role of these beliefs and expectations in moderating the relation between (perceived and actual) disease severity and depression was(More)
Cudeck and Browne (1983) were among the first to discuss the advantages of taking a crossvalidation approach to testing of covariance structure models. The purpose of this paper is to expand on Cudeck and Browne's work in two directions. The first direction of expansion is into testing of latent class models. The second direction of expansion involves using(More)