Controlling for Acquiescence Response Set in scale development.

Acquiescence response set (ARS), the tendency to agree with questionnaire statements regardless of content, is especially problematic in scale development when attitude structure is not well known, because it heightens the correlations among items that are worded similarly, even when they are not conceptually related. A partial correlation technique is described for measuring and controlling for ARS using the method of matched pairs. 1,351 persons earned an ARS score from the frequency with which they agreed with pairs of items logically opposite. Principal-components analysis was then performed on the 1st-order interitem partial correlation matrix, controlling for ARS score. Evidence is presented that this procedure reduces the average interitem correlation among like-worded items, increases the average interitem correlation among differently worded items measuring the same concept, and produces a principal components solution that is more interpretable. These conclusions emerge from comparisons with analyses of untransformed attitude scores and attitude scores excluding Ss who demonstrated the greatest acquiescence. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Factors that influence the temporal stability of personality by questionnaire.

Analyzed test–retest reliability data gathered from 106 sources (89 independent samples), using a multiple-regression method in an attempt to estimate the effects of several factors on questionnaire stability. We examined 8 self-report inventories: the High School Personality Questionnaire, the 16PF, the MMPI, the Myers–Briggs Type Indicator, the CPI, the Guilford–Zimmerman Temperament Survey, the EPPS, and the OPI. Samples ranged in size and encompassed a wide range of Ss divergent on status and age. We found S's age and status, number of test items, test interitem correlation, and test–retest interval to be significant predictors of reliability. Variables representing general adjustment were found to be less predictable than extraversion variables, and short-term reliability was more predictable than long-term reliability. S's sex and specific questionnaires were not found to have a significant effect on reliability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of spaced repetitions on amnesia patients' recall and recognition performance.

This study examined the effects of repetition and spacing of repetitions on amnesia patients' recognition and recall of a list of words. Like controls, amnesia patients recognized items better when repetitions were spaced compared with when they were massed. This finding was attributed to the additional rehearsal that distributed presentations typically encourage. Amnesia patients also showed normal spacing effects in a recall task, suggesting that they were able to benefit from the variable encoding that spaced repetitions allow to establish additional retrieval cues. However, even though instructions to encode repeated items in a variable manner enhanced massed presentations to the point where spacing no longer produced an advantage for the normal controls, it did not have a similar effect for the amnesia patients. This led to the conclusion that amnesia patients cannot take advantage of strategically provided opportunities to enhance their variable encoding of interitem associations. Instead, it is suggested that the automatic activation of different aspects of items and interitem associations is responsible for the spacing effect in their recall. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Skew reduces test-retest reliability.

Demonstrates that skew will reduce the test-retest reliability of otherwise normal data and that the greater the skew is, the greater will be the decrease in reliability. In the first section, equations are derived for the test-retest reliability of lognormal data, a skewed distribution that can be returned to normality by the log transformation. The second analytic treatment derives equations for reliability with power transformations (xa) that will produce skew in originally normal data. Finally, analysis of test-retest correlations of actual skewed measures confirmed that if skew was minimized by transformation toward symmetry, then the reliabilities increased; the increase in reliability was related to the extent of skew. Researchers are cautioned to consider transforming data that are skewed to obtain greater symmetry and, thus, improve the test-retest reliability of the resulting measure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of Skew Angle on Reinforced Concrete Slab Bridges

The effect of a skew angle on simple-span reinforced concrete bridges is presented in this paper using the finite-element method. The parameters investigated in this analytical study were the span length, slab width, and skew angle. The finite-element analysis (FEA) results for skewed bridges were compared to the reference straight bridges as well as the American Association for State Highway and Transportation Officials (AASHTO) Standard Specifications and LRFD procedures. A total of 96 case study bridges were analyzed and subjected to AASHTO HS-20 design trucks positioned close to one edge on each bridge to produce maximum bending in the slab. The AASHTO Standard Specifications procedure gave similar results to the FEA maximum longitudinal bending moment for a skew angle less than or equal to 20°. As the skew angle increased, AASHTO Standard Specifications overestimated the maximum moment by 20% for 30°, 50% for 40°, and 100% for 50°. The AASHTO LRFD Design Specifications procedure overestimated the FEA maximum longitudinal bending moment. This overestimate increased with the increase in the skew angle, and decreased when the number of lanes increased; AASHTO LRFD overestimated the longitudinal bending moment by up to 40% for skew angles less than 30° and reaching 50% for 50°. The ratio between the three-dimensional FEA longitudinal moments for skewed and straight bridges was almost one for bridges with skew angle less than 20°. This ratio decreased to 0.75 for bridges with skew angles between 30 and 40°, and further decreased to 0.5 as the skew angle of the bridge increased to 50°. This decrease in the longitudinal moment ratio is offset by an increase of up to 75% in the maximum transverse moment ratio as the skew angle increases from 0 to 50°. The ratio between the FEA maximum live-load deflection for skewed bridges and straight bridges decreases in a pattern consistent with that of the longitudinal moment. This ratio decreased from one for skew angles less than 10° to 0.6 for skew angles between 40 and 50°.     

External evaluation of efficacy by means of an Adjective Check List scale for observers.

Reports the development of an observational scale for efficacy developed from the Adjective Check List. The 42 items in the scale had interitem alpha coefficients ranging from .82 to .96 in 12 examinations, though interobserver correlations were lower, ranging from .36 to .54. In subsamples that included 236 males and 236 females, scores on the observational scale were positively related to various demographic and self-report indices of attainment, self-confidence, and personal resourcefulness. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparability of personal attitude scale administration with mail administration with and without incentive.

A sample of 127 Ss were interviewed with a 19-item Likert-type attitude scale, and a slightly abridged form of the scale was mailed to 148 Ss, half of whom were sent 25 as incentive to respond. For 8 most discriminating items, the average scale score of the mail Ss was slightly higher than the average score of the interviewed Ss. Correlations among the three groups over the 19 items were calculated for the percent of 'undecided' responses and the percent of non-favorable responses. The correlation between the two mail groups was .9 for both types of responses. The correlations between the mail groups and the interview group were slightly over .8. A higher proportion of incentive-mail respondents replied than of Ss who did not receive money. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Maximizing power in skewed distributions: Analysis and assignment.

Power and Type I error control were compared in a Monte Carlo simulation of the combinations of 2 methods of assignment to groups and 2 methods of analysis. Assignment to treatment groups was either random or systematic on the basis of alternating ranks on a concomitant variable. Analysis was either with a randomized block or analysis of covariance using the concomitant variable. The correlation between the concomitant and outcome variables was set at .2, .5, and .8. The skew of the concomitant and outcome were separately set at γ? values of 0.0, 0.75, 1.25, and 1.75. Overall the most powerful design was an analysis of covariance with systematic assignment of subjects. This superiority was particularly noticeable when the correlation was large and the distribution of the outcome variable was exponentially skewed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aortic blood momentum--the more the better for the ejecting heart in vivo?

OBJECTIVES: The aim of the present study was to test two hypotheses: (1) the momentum of the blood flowing out of the left ventricle toward the aorta (inertia force) plays an important role in the initiation of decay and the maximum rate of decay (peak (-dP/dt)) of left ventricular pressure (P); (2) a normal heart itself generates the inertia force which enhances its function. METHODS: The contribution of the inertia force to (-dP/dt) was theoretically given as rho c alpha, where rho is the blood density, c the pulse wave velocity, and alpha the deceleration rate of aortic blood flow. The correlations of peak (-dP/dt) with rho c alpha and with the time constant (tau) of the pressure decay during isovolumic relaxation, which was considered to represent myocardial relaxation characteristics, were compared in seven dogs. We developed a method of grading the strength of the inertia force, using the phase loop of left ventricular pressure (dP/dt vs. P relation). The method was applied to the records of 25 patients with ischemic heart disease, from which high fidelity left ventricular pressure recordings were available. RESULTS: The correlation of peak (-dP/dt) with rho c alpha was much higher than with tau (0.75 vs. -0.46). 16 of the 25 patients showed evidence of the inertia force. However, other patients showed no inertia force. The strength of the inertia force showed a significant (P < 0.05) correlation with left ventricular end-diastolic pressure (r = -0.46), cardiac index (r = 0.62), stroke volume index (r = 0.69), ejection fraction (r = 0.46), and peak (-dP/dt) (r = 0.56). CONCLUSION: The inertia force of late systolic aortic flow contributed to ventricular relaxation in the normal heart.     

An item analysis of Cattell's 16 PF.

Administered Form A of the 16 PF to 567 undergraduates, and obtained correlations between all items. The present analysis concerns the number of significant interitem correlations. Of the 16,836 interitem correlations, 3,267 were significant at the .01 level. Of these 3,267, only 348 were intrafactor correlations out of 984 possible significant intrafactor correlations. The most homogeneous item groupings were found in surgency, parmia, and ergic tension. In general, this widely used personality test does not satisfy critical scrutiny at the item level. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using overt rehearsals to explain word frequency effects in free recall.

Three experiments examined the word frequency effect in free recall using the overt rehearsal methodology. Experiment 1 showed that lists of exclusively high-frequency (HF) words were better recalled, were rehearsed more, and were rehearsed to more recent serial positions than low-frequency (LF) words. A small HF advantage remained even when these 2 variables were equated. Experiment 2 showed that all these effect, were much reduced with mixed lists containing both HF and LF words. Experiment 3 compared pure and mixed lists in a within-subject design and confirmed the findings of Experiments 1 and 2. It is argued that number of rehearsals, recency of rehearsals, and strength of interitem association cause the word frequency effect in free recall. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measurement properties of the RM-18. A modified version of the Roland-Morris Disability Scale

STUDY DESIGN: This investigation had two components: one was an item analysis that examined data obtained at the initial patient assessment, and the second was a validation study that used a pretest-posttest design. OBJECTIVES: The authors' goal, in this study, was to determine whether a shorter version of the Roland-Morris Questionnaire could be developed with measurement properties equal to or better than the original 24-item questionnaire. SUMMARY OF BACKGROUND DATA: The measurement properties of the Roland-Morris Questionnaire have been shown to be better than or equal to competing measures. A number of studies have reported modified versions of the Roland-Morris without providing the measurement properties of the modified tool. METHODS: The item analysis investigated endorsement frequency, interitem correlations, item-corrected item total correlations, and coefficient alpha with various combinations of items deleted. The validation study examined reliability, concurrent validity, and longitudinal validity (sensitivity to change). The analyses included comparisons with the Oswestry and Jan van Breeman Pain Questionnaires. RESULTS: The item analysis suggested than six items could be detected from the Roland-Morris Questionnaire. The validation study demonstrated that the shorter version, named the RM-18, has measurement properties that are equal to those of the longer version. CONCLUSIONS: The RM-18 can be used as an outcome measure in clinical trials or as a tool to aid in decision making concerning individual patients. In either case, its measurement properties are equal to those of the 24-item Roland-Morris Questionnaire.     

Effect of the violation of assumptions upon significance levels of the Pearson r.

Conducted a study to determine empirically the effects of the violation of assumptions of normality and of measurement scales on the Pearson product-moment correlation coefficient. The effects of such violations were studied separately and in combination for samples varying in size from 5 to 60. Monte Carlo procedures were used to generate populations of scores for 4 basic distributions: normal, positively skewed, negatively skewed, and leptokurtic. Samples of varying sizes were then randomly selected from specific populations. Results were based on distributions of r , which were calculated on 5,000 sets of samples of n = 5 or n = 15 and 3,000 sets of samples of n = 30 or n = 60. Results indicate that the Pearson r is insensitive to extreme violations of the basic assumptions of normality and of the type of measurement scale. Failure to meet the basic assumptions separately or in combination had little effect on the obtained distributions of r s based on rho of zero. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

La comparaison de trois méthodes psychométriques utilisées dans les questionnaires d'attitudes.

13 motivations to work were rated by 35 students according to 3 different psychometric methods: paired comparisons, ranking, and a Likert-type scale. For the Likert-type scale, the ratings fell at the upper end of the possible continuum. However, the real range was restricted when the other 2 methods were used because of a "piling-up" effect. There was no difference in terms of the variability in judgments obtained by the 3 methods. The Likert-type scale yielded distributions which were more negatively than positively skewed. Variability and skewness were both affected by the "piling-up" effect. Regardless of the method used, all 35 Ss were in substantial agreement in their evaluations of the 13 motivations, but there were individual differences in the degree of consistency of the answers of each S from one form of the questionnaire to the other. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of chlorine substitution on the dermal absorption of polychlorinated biphenyls

This study investigated the characteristics of computer-based case simulations (CCS) that may be associated with case difficulty. Difficulty was defined as the average rating by physicians of examinee performance on a nine-point scale or the passing rate on the cases. Two data sets were used, one from an administration of 18 cases, the other from an administration of 22 cases with 13 cases used on both occasions. Stepwise regression procedures were used separately for case properties and for analytic scoring of key variables to identify the best sets of predictors of case difficulty. Because of the small number of cases, regression results were evaluated for consistency across both data and both difficulty measures. For key variables, the best set of predictors included the number of different serious errors of commission, risk items, and benefit items. In general, cases were more difficult for higher values of these variables. For case variables, the only consistent variable was the length of the paragraph that provided patient history, with longer paragraphs associated with more difficult cases. Other variables were less consistent, but were often related to the structure of the simulation or the severity of the patient condition. Although the findings for case variables were limited, the analyses were very helpful in illuminating the interconnections among the variables within cases.     

On the remembrance of times past: The irregular list technique.

Four experiments were designed to examine the processing of time in human memory. These experiments introduce a new way of testing memory for relative temporal duration that uses a list with uneven temporal spacing between items. In this irregular list technique, people are excused from remembering the items themselves and from remembering their relative positions within the list but must judge which of two adjacent interitem intervals had been longer. Although performance was good in this task, it was comparable for vocalized and silent visual presentation. This finding directly contradicts the hypothesis that temporal coding is better in the auditory modality than in the visual modality. The second experiment replicated this result for word lists under conditions in which people were ignorant, until after list presentation, about whether they were to recall the items or to make temporal judgments. The third experiment investigated the effect of filling, with distraction, the interitem intervals in irregularly spaced lists. In the final experiment, we adapted the irregular list technique to examine long-term or semantic memory. We conclude that memory for the genuinely temporal properties of learned experiences can and should be separated from their sequential ordering. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Averaging correlation coefficients: Should Fisher's z transformation be used?

Averaging correlations leads to underestimation because the sampling distribution of the correlation coefficient is skewed. It is also known that if correlations are transformed by Fisher's z prior to averaging, the resulting average overestimates the population value of z. The behavior of these procedures for averaging correlations was investigated via Monte Carlo simulation, both in terms of bias (under- and overestimation) and precision (standard errors). It was found that average z backtransformed to r is less biased positively than average r is biased negatively. The standard error of average r was smaller than that of average z when the population correlation was small; however, the reverse was true when the population correlation exceeded .5. Regardless of sample size, back transformed average z was always less biased; therefore, the use of the z transformation is recommended when averaging correlation coefficients, particularly when sample size is small. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The continuing dilemma concerning medical versus surgical management of patients with acute type B dissections

In the free-running circadian rhythms of 14 human subjects (4 females, 10 males) who lived singly in an isolation unit without temporal clues, locomotor activity was recorded by means of contact plates installed below the carpet in the main room. During sleep, movements in bed were picked up by spring contacts attached to the mattress. In all subjects, the hourly means of locomotion during wakefulness (alpha) were negatively correlated with the duration of alpha to such an extent that the total amount of locomotion per cycle remained constant when alpha varied from 14 to 23 hr. The hourly values of movements in bed were independent of the duration of sleep (rho), so that the total number of movements was almost proportional to rho. The "homeostatic control" of locomotion during wake time is considered as a means to conserve energy when the duration of wakefulness increases.     

Age-related changes in children's perceptions of aggression and withdrawal in their peers.

Collected peer ratings of aggression, withdrawal, and likeability using the Pupil Evaluation Inventory (PEI) with 326 1st graders, 356 4th graders, and 298 7th graders. Measures of the perceived similarity of all possible pairs of PEI items were derived by computing the frequency with which Ss at each grade level were concurrently nominated by their peers for both items comprising each pair of items. Multidimensional scaling was then employed to elucidate the structure underlying these indices of interitem similarity. Structure ratios denoting the cohesiveness of the clusters of aggression, withdrawal, and likeability items were computed from the results of these analyses. Data show that for Ss of all ages, aggression items and likeability items comprised highly cohesive categories of behaviors that were distinct from each other. Withdrawal items, in contrast, clustered poorly at Grade 1 but became an increasingly cohesive category of behaviors and increasingly distinct from aggression as grade level increased. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Part-list cuing can be transient and lasting: The role of encoding.

The presentation of a subset of learned items as retrieval cues can have detrimental effects on recall of the remaining items. For 2 types of encoding conditions, the authors examined in 3 experiments whether such part-list cuing is a transient or a lasting phenomenon. Across the experiments, the detrimental effect of part-list cues was consistently found to be transient with a high degree of interitem associations and lasting with a low degree. These results indicate that the persistence of part-list cuing depends on encoding, thus challenging both strategy disruption and retrieval inhibition as general accounts of part-list cuing. A 2-mechanism account is provided according to which the 2 mechanisms mediate the effect in different encoding conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)