Testing for DIF in a model with single peaked item characteristic curves: The parella model

The PARELLA model is a probabilistic parallelogram model that can be used for the measurement of latent attitudes or latent preferences. The data analyzed are the dichotomous responses of persons to items, with a one (zero) indicating agreement (disagreement) with the content of the item. The model provides a unidimensional representation of persons and items. The response probabilities are a function of the distance between person and item: the smaller the distance, the larger the probability that a person will agree with the content of the item. This paper discusses how the approach to differential item functioning presented by Thissen, Steinberg, and Wainer can be implemented for the PARELLA model. Requests for the PARELLA software should be sent to Iec Progamma PO Box 841, 9700 AV Groningen, The Netherlands.     

Statistical inference based on latent ability estimates

The quality of approximations to first and second order moments (e.g., statistics like means, variances, regression coefficients) based on latent ability estimates is being discussed. The ability estimates are obtained using either the Rasch, or the two-parameter logistic model. Straightforward use of such statistics to make inferences with respect to true latent ability is not recommended, unless we account for the fact that the basic quantities are estimates. In this paper true score theory is used to account for the latter; the counterpart of observed/true score being estimated/true latent ability. It is shown that statistics based on the true score theory are virtually unbiased if the number of items presented to each examinee is larger than fifteen. Three types of estimators are compared: maximum likelihood, weighted maximum likelihood, and Bayes modal. Furthermore, the (dis)advantages of the true score method and direct modeling of latent ability is discussed.     

Humor As a Stress Moderator in the Prediction of Blood Pressure Obtained during Five Stressful Tasks

In five consecutive stressful tasks we examined the role of humor as a potential stress moderator using systolic and diastolic blood pressure as an indication of cardiovascular reactivity. In all five tasks, the Coping Humor Scale interacted with sex in the prediction of blood pressure. The same pattern was found in response to each of the five tasks: Females who were higher in coping humor exhibited lower systolic blood pressure than females scoring lower on coping humor, while the reverse characterized males; males who scored high on the coping humor scale exhibited higher systolic blood pressure than males scoring low on that scale. Similar though less robust results were found when the Situational Humor Response Questionnaire was used as the measure of humor. In the Cold Pressor Task, which involves pain and endurance, interactions were found between humor, sex, and trials indicating a stress-moderator effect. The absence of interactions indicating stress moderation in most of the analyses with the other four stress tasks suggests that humor may play more of a role in moderating the impact of uncontrollable and passively experienced stressors. Tasks requiring more active, problem-solving behavior may be less amenable to the beneficial effects of humor. The findings do not clearly resolve the questions about the role of humor in effecting responses to stress. However, they do suggest that the subjects' sex may be an important consideration when evaluating the impact of humor as a stress moderator.     

Family systems in premarital counseling

Rooted in Bowenian family systems theory, a format for pastoral premarital counseling is described. Examples are cited which show how couples can be helped to look at the formation of their own marital unit by studying each partner's family of origin system.     

Distortions and deceptions in self presentation: Effects of protracted litigation in personal injury cases

The goal of diagnostic examinations in personal injury lawsuits is to ascertain genuineness and substantiality of claimed impairments so that ‘damages’ can be accurately defined. These examinations require consideration of the potential role of malingering and other deceptive response styles in determining the nature and extent of impairment. Involvement in litigation renders plaintiffs susceptible to stressors and to influences that may lead to increased impairment, biased reportage, and retarded recovery. Underlying personality patterns play a critical role in defining and shaping reactions to trauma, to the stress of litigation, and to treatment interventions. Protracted litigation creates conditions that promote mnemonic and attitudinal distortions, as well as conscious and unconscious motivations for secondary gain. The presence of non-legally relevant factors provides the opportunity for proportionate attribution of causation. An assessment model is proposed for analyzing elements of causation.     

On re-scaleability of force and time in aiming movements

Summary Evidence for invariant relative timing is mostly based on comparisons between experimental conditions which differ in the average speed of the movements under study. The present experiment examines whether spontaneous variability of acceleration-time curves of aiming movements within a single experimental condition can also be described in terms of variable scaling parameters for both dimensions. This requires that the correlations between peak acceleration and peak deceleration, as well as those between time intervals defined by peak values and zero crossings, are high. In extensions of the elbow joint on a horizontal plane, the latter correlations turned out to be small or even negative. These results cannot be explained as being due to artifacts of several origins. To reconcile them with those based on comparisons between experimental conditions, a dual-level hypothesis of control in aiming movements is suggested. Only variability on one level can be described in terms of variable scaling parameters, and whether or not variability of acceleration-time curves can be described in this way depends on the relative contributions of both levels of control.     

Uses of hypnosis in evaluating malingering and deception

Hypnosis, as a method of detecting deception, is examined with respect to its forensic applications. The degree of hypnotizability and whether formal hypnotic procedures may be employed are discussed with both the relevant clinical and legal issues in mind. Finally, the use of hypnosis in determining the authenticity of psychosomatic conditions is addressed.     

The functional equivalence of problem solving skills

The tower of Hanoi problem is used to show that, even in simple problem environments, numerous distinct solution strategies are available, and different subjects may learn different strategies. Four major classes of solution strategies are described for the problem. Different strategies have different degrees of transferability, place different burdens on short-term memory and on perception, and require different learning processes for their acquisition. The analysis underscores the importance of subject-by-subject analysis of “what is learned” in understanding human behavior in problem-solving situations, and provides a technique for describing subjects' task performance programs in detail.     

Reinforcement from the sucking environment and subsequent modification of sucking behavior in the human neonate

The reinforcing aspects of sucking behavior in 36 human newborns was examined in a limited instrumental conditioning paradigm where sucking was both operant and reinforcer. During training, response density (rate based on sucking opportunity time) and latency were measures of two components of nonnutritive sucking, contingent negative pressure suction, and incidental jaw movement. The strategy for determining the reinforcing aspects of sucking involved comparisons of three types of sucking stimuli as reinforcers. The nature of modified operant sucking was investigated during extinction by examining number of sucks per burst, number of bursts emitted, and interburst interval time. The feedback from sucking which acted as reinforcement was concluded to be response density. Sucking was modified by changes in pausing behavior, including response latency and pauses between bursts of sucks. The number of sucks per burst also showed a significant change under certain conditioning arrangements.