A note on parameter estimation for Lazarsfeld's latent class analysis

As the literature indicates, no method is presently available which takes explicitly into account that the parameters of Lazarsfeld's latent class analysis are defined as probabilities and are therefore restricted to the interval [0, 1]. In the present paper an appropriate transform on the parameters is performed in order to satisfy this constraint, and the estimation of the transformed parameters according to the maximum likelihood principle is outlined. In the sequel, a numerical example is given for which the basis solution and the usual maximum likelihood method failed. The different results are compared and the advantages of the proposed method discussed.     

Clinical management of alcohol withdrawal

It has been well known for a number of years that abrupt withdrawal from alcohol following chronic use is associated with adverse consequences, ranging from mild tremors to withdrawal seizures. The overall purposes of treating alcohol withdrawal (AW) are to relieve patient discomfort, to prevent the development of more serious withdrawal symptoms, and to initiate long-term alcohol rehabilitation. Several areas of controversy exist in the clinical management of AW, including the optimal treatment setting, the need for pharmacologic management, and the most appropriate agent to prescribe when medication is deemed necessary. This article reviews the clinical features, general management, and treatment of AW.     

The wisdom of nature in integrating science, ethics and the arts

This paper deals with an approach to the integration of science (with technology and economics), ethics (with religion and mysticism), the arts (aesthetics) and Nature, in order to establish a world-view based on holistic, evolutionary ethics that could help with problem solving. The author suggests that this integration is possible with the aid of “Nature’s wisdom” which is mirrored in the macroscopic pattern of the ecosphere. The corresponding eco-principles represent the basis for unifying soft and hard sciences resulting in “deep sciences”. Deduction and induction will remain the methodology for deep sciences and will include conventional experiments and aesthetic and sentient experiences. Perception becomes the decisive factor with the senses as operators for the building of consciousness through the subconscious. In this paper, an attempt at integrating the concepts of the “true”, the “right” and the “beautiful” with the aid of Nature’s wisdom is explained in more detail along with consequences. The author is a bioprocess engineer with a research interest in environmental issues.     

Correction to: Exploring Latent Profiles of Psychopathology in a Sample of Lonely People Seeking Treatment

Journal of Psychopathology and Behavioral Assessment -     

The Effect of Method Characteristics on Retest Score Gains and Criterion-Related Validity

Purpose

We sought to empirically assess the effect of predictor method characteristics (test form, item-type, and test-type) on retest score change associated with an invariant construct—general mental ability (GMA)—and to evaluate the effect of retesting on the criterion-related validity of assessments that vary in their susceptibility to retest effects.

Design

Three hundred seven individuals completed a battery of GMA assessments. After a 6-week interval, participants returned to the testing site to retest using both alternate and identical forms of the initial assessments.

Findings

Greater score gains were observed on assessments comprising heterogeneous item-types than homogeneous item-types, and on performance-based assessments than self-report assessments. However, despite variations in score gains, the relationships between the initial test scores and criterion scores were no different than the relationships between retest scores and criterion scores for all assessments.

Implications

Tests and procedures that reduce reliance on test- or item-specific knowledge and skill may help minimize score changes due to retesting across multiple administrations. Moreover, under the boundary conditions present in this study, the criterion-related validity of ability assessments may not be affected by increases in test-specific knowledge and skills.

Originality/Value

Despite the prevalence and industry support of retesting, a comprehensive understanding of retest score change still eludes researchers and practitioners. This ambiguity may be due in part to neglecting the method-construct distinctions in the retest literature. This is the first report to explicitly utilize the method-construct distinction in an effort to examine the causes and consequences of retest effects.

     

Instruction-driven processing in human perceptual learning

We conducted a series of experiments to determine the relative contribution of unsupervised versus controlled mechanisms to the intermixed-blocked effect. In Experiment 1, participants received pre-exposure instructions prompting a search for differences between stimuli, in keeping with past studies, and the intermixed-blocked effect was observed. In the remaining experiments, participants did not receive the aforementioned instructions, but instead were instructed either to simply observe the stimuli (Experiment 2) or in relation to a masking task (Experiment 3). None of the latter experiments produced an intermixed-blocked effect, suggesting that the effect found in Experiment 1 was driven by the instructions to search for differences, consistent with a controlled processing account of the effect. Moreover, we tested a prediction assuming the operation of a search strategy against one assuming the operation of a short-term habituation mechanism and found evidence more consistent with the search strategy hypothesis. We formulate a new account of the intermixed-blocked effect in humans based on an instruction-driven search and discuss how the account could explain many findings in the human literature.     

Optimal assertions,and what they implicate. A uniform game theoretic approach

To determine what the speaker in a cooperative dialog meant with his assertion, on top of what he explicitly said, it is crucial that we assume that the assertion he gave was optimal. In determining optimal assertions we assume that dialogs are embedded in decision problems (van Rooij 2003) and use backwards induction for calculating them (Benz 2006). In this paper, we show that in terms of our framework we can account for several types of implicatures in a uniform way, suggesting that there is no need for an independent linguistic theory of generalized implicatures. In the final section, we show how we can embed our theory in the framework of signaling games, and how it relates with other game theoretic analyses of implicatures.

Equivalence of paper and pencil vs Internet forms of the ZKPQ-50-CC in Spanish and French samples

This study was designed to check for the equivalence of the ZKPQ-50-CC (Spanish and French versions) through Internet on-line (OL) and paper and pencil (PP) answer format. Differences in means and deviations were significant in some scales, but effect sizes are minimal except for Sociability in the Spanish sample. Alpha reliabilities are also very similar in both versions with no significant differences between formats. A robust factorial structure was found for the two formats and the average congruency coefficients were 0.98. The goodness-of-fit indexes obtained by confirmatory factorial analysis are very similar to those obtained in the ZKPQ-50-CC validation study and they do not differ between the two formats. The multi-group analysis confirms the equivalence among the OL–PP formats in both countries. These results in general support the validity and reliability of the Internet as a method in investigations using the ZKPQ-50-CC.