Asymptotic clarifications,generalizations, and concerns regarding an extended class of matched pairs tests based on powers of ranks

Recent studies pertaining to an extended class of matched pairs tests based on powers of ranks are discussed. Previous questions regarding the asymptotic properties for this class of tests are clarified and a generalization of this class is described. This generalization raises a previously unanticipated concern about whether or not the analytic comparisons resulting from these tests correspond with an intuitive notion of what is being compared.     

Statistical inference based on ranks

This paper develops a unified approach, based on ranks, to the statistical analysis of data arising from complex experimental designs. In this way we answer a major objection to the use of rank procedures as a major methodology in data analysis. We show that the rank procedures, including testing, estimation and multiple comparisons, are generated in a natural way from a robust measure of scale. The rank methods closely parallel the familiar methods of least squares, so that estimates and tests have natural interpretations.This research was supported in part by grant MCS76-07292 from the National Science Foundation.     

Power comparisons of significance tests of location using scores,ranks, and modular ranks

The Type I error probability and the power of the independent samples t test, performed directly on the ranks of scores in combined samples in place of the original scores, are known to be the same as those of the non‐parametric Wilcoxon–Mann–Whitney (WMW) test. In the present study, simulations revealed that these probabilities remain essentially unchanged when the number of ranks is reduced by assigning the same rank to multiple ordered scores. For example, if 200 ranks are reduced to as few as 20, or 10, or 5 ranks by replacing sequences of consecutive ranks by a single number, the Type I error probability and power stay about the same. Significance tests performed on these modular ranks consistently reproduce familiar findings about the comparative power of the t test and the WMW tests for normal and various non‐normal distributions. Similar results are obtained for modular ranks used in comparing the one‐sample t test and the Wilcoxon signed ranks test.     

Generalization of ratings based on projective tests

Abstract.— A multivariable-multimethod analysis was performed on six professional clinical psychologists' ratings of 38 patients for the three variables, Intelligence, Ability to Establish Contact and Control of Affect and Impulses. The judges based their ratings of the patients performance on each of the three tests Rorschach, TAT, and Sentence Completion separately as well as on all tests together. The stability coefficients and the consensus among judges was rather high but decreased when the depth of interpretation of the response variable increased. The ratings showed both convergent and discriminant validity but the generality of the ratings was generally low. The results support the opinions held among clinicians, that tests give different kinds of information about individuals and that clinicians, to some extent, use the information from each test as a subvariable which is integrated into a more global variable.     

An exploratory study of cognitive style in performance on matched and mismatched tasks

Researchers have suggested that task performance is often dependent upon the congruence of cognitive style and task. To explore this suggestion, 44 female and 4 male undergraduates were administered the Cognitive Style Analysis, the Closure Flexibility, the Composite Gestalt Completion Test, and the Vocabulary subtest from the WAIS. Specifically, four hypotheses were tested: (1) that participants with an analytic style will perform better than those with a wholistic style on the Closure Flexibility; (2) that participants with a wholistic style will perform better than those with an analytic style on the Composite Gestalt Completion Test; (3) that participants with an intermediate style will outperform persons with an analytic style on the Composite Gestalt Completion Test; and (4) that intermediate scorers would perform better than those with a wholistic style on Closure Flexibility. Only the second hypothesis was supported, so results provide only minimal support for the effect of match or mismatch of cognitive style and task performance.     

An extended comparator hypothesis account of superconditioning

Three conditioned taste aversion experiments with rats investigated superconditioning. In each experiment, alternate exposures of 2 flavor compounds with a common element (i.e., AB/AS) were administered to establish an inhibitory relationship between the 2 unique elements, B and S, and prior to testing, S was paired with lithium chloride (LiCl). In Experiment 1, pairings of a neutral cue (X) with S in compound with B after the AB/AS exposures resulted in superconditioning between X and S. Extinction of the common element (A) just before the S-LiCl pairing attenuated both the inhibitory relationship between B and S (Experiment 2) and superconditioning between X and S (Experiment 3). These observations suggest that superconditioning consists of enhanced performance rather than enhanced associative acquisition.     

An accumulator model for responses and response times in tests based on the proportional hazards model

Latent trait models for responses and response times in tests often lack a substantial interpretation in terms of a cognitive process model. This is a drawback because process models are helpful in clarifying the meaning of the latent traits. In the present paper, a new model for responses and response times in tests is presented. The model is based on the proportional hazards model for competing risks. Two processes are assumed, one reflecting the increase in knowledge and the second the tendency to discontinue. The processes can be characterized by two proportional hazards models whose baseline hazard functions correspond to the temporary increase in knowledge and discouragement. The model can be calibrated with marginal maximum likelihood estimation and an application of the ECM algorithm. Two tests of model fit are proposed. The amenability of the proposed approaches to model calibration and model evaluation is demonstrated in a simulation study. Finally, the model is used for the analysis of two empirical data sets.     

Penile responses of rats (Rattus norvegicus) in extended ex copula tests

Prolonged tests of rats' penile responses outside the context of copulation (ex copula) were undertaken to facilitate analysis of these penile components of copulatory behavior. Penile erections and flips were evoked for 1 hr following penile sheath retraction (SR), and rats were retested for 30 min after a rest interval of 5 min to 4 hr. The number of penile responses declined sharply over the course of the hour. Following a 5-min rest, there was little likelihood of additional responses. Within 2 hr some measures of penile response potential approached their original high asymptotes; other measures were still depressed after 4-hr rest. In control tests, the penile sheath was unretracted (SU) during the first 60 min, and hence few or no penile responses occurred. This condition caused no reduction in the number of erections and flips in the subsequent 30-min SR test; hence the reduction in response potential during and after SR tests was due to the responses displayed, not to the conditions of restraint. Ejaculation occurred frequently in the SU condition but rarely in SR tests, results suggesting that sheath retraction may normally inhibit ejaculation in ex copula tests, and perhaps during copulation as well.     

An evaluation of the effects of matched stimuli on behaviors maintained by automatic reinforcement

The purpose of the current investigation was to extend the literature on matched stimuli to three dissimilar forms of aberrant behavior (dangerous climbing and jumping, saliva manipulation, and hand mouthing). The results of functional analyses suggested that each behavior was automatically reinforced. Preference assessments were used to identify two classes of stimuli: items that matched the hypothesized sensory consequences of aberrant behavior (matched stimuli) and items that produced sensory consequences that were not similar to those produced by the aberrant behavior (unmatched stimuli). The effects of providing continuous and noncontingent access to either the most highly preferred matched or the most highly preferred unmatched stimuli were assessed relative to a condition in which no stimuli were available. Overall results suggested that providing access to items that matched the hypothesized sensory consequences of aberrant behavior may be more effective than simply selecting stimuli either arbitrarily or based on the results of preference assessments alone.     

An evaluation of the effects of response interruption redirection and matched stimulation on vocal stereotypy

Stereotypy is one of the core diagnostic features of autism spectrum disorder and warrants behavioral intervention when it negatively impacts the person's life. The aim of this study was to evaluate the effectiveness of noncontingent matched stimulation (NCR‐M) compared with response interruption redirection (RIRD) on reducing levels of vocal stereotypy in the natural environment. Interventions were compared using an alternating treatments design followed by generalization and maintenance phases, which utilized lay people as instructors. Results showed that both RIRD and NCR‐M resulted in a reduction in vocal stereotypy for three out of four participants within an educational setting. An increase in appropriate vocalizations was found for two out of four participants for both interventions. These results suggest that both NCR‐M and RIRD were effective in reducing levels of vocal stereotypy, yet their effects on appropriate communication remain undetermined. Social validity scores were obtained following the study, which demonstrated that both interventions were met with approval across a variety of measures.     

Active heading control in simulated flight based on vertically extended contours

In two experiments, we manipulated the properties of 3-D objects and terrain texture in order to investigate their effects on active heading control during simulated flight. Simulated crosswinds were used to introduce a rotational component into the retinal flow field that presumably provided the visual cues used for heading control An active control task was used so that the results could be generalized to real-world applications such as flight simulation. In Experiment 1, we examined the effects of three types of terrain, each of which was presented with and without 3-D objects (trees), and found that the presence of 3-D objects was more important than terrain texture for precise heading control In Experiment 2, we investigated the effects of varying the height and density of 3-D objects and found that increasing 3-D object density improved heading control, but that 3-D object height had only a small effect. On the basis of these results, we conclude that the vertical contours improved active heading control by enhancing the motion parallax information contained in the retinal flow.     

Monte Carlo tests of the Rasch model based on scalability coefficients

For item responses fitting the Rasch model, the assumptions underlying the Mokken model of double monotonicity are met. This makes non‐parametric item response theory a natural starting‐point for Rasch item analysis. This paper studies scalability coefficients based on Loevinger's H coefficient that summarizes the number of Guttman errors in the data matrix. These coefficients are shown to yield efficient tests of the Rasch model using p‐values computed using Markov chain Monte Carlo methods. The power of the tests of unequal item discrimination, and their ability to distinguish between local dependence and unequal item discrimination, are discussed. The methods are illustrated and motivated using a simulation study and a real data example.     

An objective technique for recording shock-induced aggression in unrestrained pairs of rats

Pairs of rats received grid shock in a conical enclosure. Each shock elicited the stereotyped fighting posture. An omnidirectional pole, which was always between the rats, was accidentally operated whenever the rats fought. The number of pole hits, and the number of observed fight bouts, increased with current intensity. The number of pole hits served as a reliable and objective measure of shock-induced fighting in rats.     

Predicting preference for items during periods of extended access based on early response allocation

Top‐ranked items were identified during 30‐min free‐operant preference assessments for 9 individuals. Data from each session were analyzed to identify the item (a) that was engaged with first in each session and (b) to which the most responding was allocated after 5 min, 10 min, 15 min, 20 min, and 25 min had elapsed in each session. The results indicated that the first‐engaged item and the 5‐min high‐allocation item predicted the top‐ranked item in 55% and 62% of the sessions, respectively. The results also showed that engagement with the top‐ranked item from the first session decreased across subsequent sessions for 6 of the 9 participants. The implications of the results for brief versus extended stimulus preference assessments are discussed.     

Normative data for eight neuropsychological tests based on a Danish sample

Normative neuropsychological data have been provided using a sample of 101 persons aged 20 to 54 years. Eighty-seven of the subjects were recruited among patients who had undergone minor surgery, and 14 subjects were volunteers from the staff at the hospital laundry. The measures consisted of seven subjects from the WAIS-R, the trail-making test, symbol digit modalities test, auditory-verbal learning test, story recall test, visual gestalt test, recurring figures test, verbal fluency, and Purdue pegboard test. These measures were selected because of suitability in regard to time taken for testing each subject and their sensitivity to subtle changes in neuropsychological functioning. The sample was arbitrarily divided into three age groups, and for each of the three samples, mean, standard deviation, and range were calculated for each test. The results of the Information and Vocabulary subtests from the WAIS-R, education, and social status were applied as independent variables in linear regression analyses where each of the neuropsychological tests, in turn, was the dependent variable. For the oldest age group, age in addition was used as an independent variable. Significant linear relationships, which accounted for an optimal part of the variance, were selected for clinical application.