Corrected item-test correlations

Previous papers on this subject derive the correlation between an item and the remainder of the test. This correlation is unsatisfactory because the reliability of the remainder varies inversely with the reliability of the item omitted. The present paper derives the correlation between an item and the total test, with that item replaced by a rationally equivalent item. The general formula is then modified, for dichotomus items, to give the corrected point-biserial, biserial, and Brogden biserial correlations. The results apply strictly only to factorially homogeneous tests: those in which the same trait or combination of traits is measured (apart from error) by every item.     

An empirical study of medical termination of pregnancy

Several studies (Senturia and Rothman, 1967; Simon et al., 1969; Stewart et.al., 1973) have shown that therapeutic abortion may be accompanied by various psychological problems (e.g., psychiatric illness, confused sexual identity, sadomasochism). This study attempts to determine the personality characteristics, e.g., extraversion-introversion, neuroticism-stability and manifest anxiety of women who seek abortion and compare them with a control group. The Eysenk Personality Inventory and the Manifest Anxiety scale adapted by George (1965, 1974) were administered to 2 groups, the experimental group (n=50; mean age, 25.8) consisting of women seeking abortion, and the control group (n=30; mean age, 25.4 years; matched for age and socioeconomic status with the experimental). Mean values for extraversion-introversion, neuroticism-stability, and manifest anxiety for the experimental group were 11.08, 15.5 and 23.74 respectively. Corresponding figures for the control group were 11.00, 10.46, and 11.96 respectively. The results show that the experimental group differed significantly from the control group in the dimensions of neuroticism and manifest anxiety. No significant differences were found between the 2 groups in terms of extraversion. The stressful nature of pregnancy is briefly discussed.     

An empirical study of seriously disturbed suicidal patients

Aspects of unconscious processes in a group of seriously disturbed psychiatric patients are examined in an effort to predict near-lethal suicide attempts and explore psychoanalytic formulations of suicide. The Rorschach Inkblot Test, the most widely used projective measure in suicide research (Bongar 1991), was chosen for its potential to shed light on specific unconscious processes. Psychic states commonly associated with suicide were measured by psychoanalytic Rorschach analog scales and then subjected to a progression of statistical analyses in order to predict future occurrence and lethality of suicide attempts. On the basis of a priori hypotheses, the authors developed a suicide index comprising four psychoanalytic Rorschach signs that predicted, with considerable accuracy, which patients would later make near-lethal suicide attempts. The best predictors were unconscious processes indicative of penetrating affective overstimulation, disturbance in the capacity to maintain adequate ego boundaries, and depressive affective states characterized by a morbid preoccupation with death and inner decay. These findings provide empirical support for several well-known formulations of the unconscious motivations for suicide.     

An empirical study of the diathesis-stress theory of disease

One thousand, one hundred and twenty-one Jewish concentration camp survivors were compared with 367 Jewish controls who had not been in a concentration camp, and had not lost any family members in such a camp. Of interest was the mortality of camp and comparison groups, on the hypothesis that the stress of being in a camp would adversely affect inmates. It was found that former camp inmates were over twice as likely to die of cancer, coronary heart diesease, or other causes as the comparison subjects of similar age and sex composition, and that severity of stress was correlated with mortality in the expected direction. Diathesis, determined by means of a special interviewer-administrated questionnaire, was found to interact synergistically with stress in producing high mortality.     

An empirical study of the validity of handwriting analysis

The EPQ was administered to 99 Ss, and a handwriting sample provided by each. A professional graphologist undertook to analyse the handwritings, and fill in the EPQ as she thought would have been done by the respondents. Significant correlations were only obtained for the P category; neither E, nor N, nor the L scale showed significant correlations between Ss and the graphologist.     

An empirical study of the factor analysis stability hypothesis

Note is taken of four related sources of confusion as to the usefulness of Thurstone's factor analysis model and of their resolutions. One resolution uses Tucker's distinction between exploratory and confirmatory analyses. Eight analyses of two sets of data demonstrate the procedures and results of a confirmatory study with statistical tests of some, but not all, relevant hypotheses in an investigation of the stability (invariance) hypothesis. The empirical results provide estimates, as substitutes for unavailable sampling formulations, of effects of variation in diagonal values, in method of factoring, and in samples of cases. Implications of these results are discussed.The computational costs of this study were defrayed, in part, by a research small grant M-1922 from the National Institute of Health, and, in part, by support under project 176-0002 by the University of Iowa Computing Center, Dr. J. P. Dolch, Director. The assistance of Dr. Kern Dickman and Mr. Leonard Wevrick of the University of Illinois and of Mr. Norman Luther of the University of Iowa in handling the computing problems is gratefully acknowledged.     

An empirical study of a logistic mental test model

A logistic model developed by Birnbaum was tested in two ways. First, plots of proportions of subjects in different score categories were examined for consistency with the assumption of a logistic trace line, and especially for departures from the logistic which seemed due to guessing in multiple choice items. The results showed that guessing seemed to have little effect. Second, an attempt was made to predict the obtained score distributions of samples of subjects on six tests from item parameters estimated on independent samples. The fits were good in all cases, despite considerable differences between the tests, and some extremely odd distributions.Thanks are due to the Educational Testing Service for the generous provision of the data upon which Part I of this study and the analysis of the two set I tests was based and to J. Lumsden for the data of the four set II tests. I would also like to thank F. M. Lord and A. Birnbaum for valuable help in the formulation and conduct of the study.At the University of Michigan 1964–65.     

An empirical study of the traditional Mach card effect

The traditional achromatic Mach card effect is an example of lightness inconstancy and a demonstration of how shape and lightness perception interact. We present a quantitative study of this phenomenon and explore the conditions under which it occurs. The results demonstrate that observers show lightness constancy only when sufficient information is available about the light-source position, and the perceptual task required of them is surface identification rather than direct colour-appearance matching. An analysis and comparison of these results with the chromatic Mach card effect (Bloj et al 1999 Nature 402 877-879) demonstrate that the luminance effects of mutual illumination do not account for the change in lightness perception in the traditional Mach card.     

The neurophenomenology of early psychosis: An integrative empirical study

BackgroundThe integration of various domains or levels of analysis (clinical, neurobiological, genetic, etc.) has been a challenge in schizophrenia research. A promising approach is to use the core phenomenological features of the disorder as an organising principle for other levels of analysis. Minimal self-disturbance (fragility in implicit first-person perspective, presence and agency) is emerging as a strong candidate to play this role. This approach was adopted in a previously described theoretical neurophenomenological model that proposed that source monitoring deficits and aberrant salience may be neurocognitive/neurobiological processes that correlate with minimal self-disturbance on the phenomenological level, together playing an aetiological role in the onset of schizophrenia spectrum disorders. The current paper presents full cross-sectional data from the first empirical test of this model.MethodsFifty ultra-high risk for psychosis patients, 39 first episode psychosis patients and 34 healthy controls were assessed with a variety of clinical measures, including the Examination of Anomalous Self-Experience (EASE), and neurocognitive and neurophysiological (EEG) measures of source monitoring deficits and aberrant salience.ResultsLinear regression indicated that source monitoring (composite score across neurocognitive and neurophysiological measures), with study group as an interaction term, explained 39.8% of the variance in EASE scores (R² = 0.41, F(3,85) = 14.78, p < 0.001), whereas aberrant salience (composite score) explained only 6% of the variance in EASE scores (R² = 0.06, F(3,85) = 1.44, p = 0.93). Aberrant salience measures were more strongly related to general psychopathology measures, particularly to positive psychotic symptoms, than to EASE scores.DiscussionA neurophenomenological model of minimal self-disturbance in schizophrenia spectrum disorders may need to be expanded from source monitoring deficits to encompass other relevant constructs such as temporal processing, intermodal/multisensory integration, and hierarchical predictive processing. The cross-sectional data reported here will be expanded with longitudinal analysis in subsequent reports. These data and other related recent research show an emerging picture of neuro-features of core phenomenological aspects of schizophrenia spectrum disorders beyond surface-level psychotic symptoms.     

The stability of depressive symptoms in college students: An empirical demonstration of regression to the mean

In a recent paper, Vredenburg, Flett, and Krames (1993) hypothesized that the apparent instability of depressive symptom scores in college students may be due, in part, to the phenomenon known as statistical regression to the mean. This statistical principle was demonstrated in the current study. A sample of 183 university students completed the Beck Depression Inventory (BDI) at two timepoints separated by a 3-month interval. Consistent with past results, analyses revealed substantial changes in symptom scores over time with decrements being evident among many subjects with elevated symptom scores at Time 1. Examination of the amount of change over time in BDI scores indicated a pattern of findings that approximated the regression to the mean phenomenon. Statistical tests confirmed that regression to the mean accounted for a significant amount of the change in symptom scores over time. The implications of these findings are discussed in terms of the nature of depressive symptoms in students and the inappropriateness of assigning subjects to depressed or nondepressed groups on the basis of elevated scores on a self-report measure.     

Interrogative suggestibility and delinquent boys: An empirical validation study

This study has several aims. First, to validate the Gudjonsson Suggestibility Scale (GSS) among delinquent and adolescent boys placed in an assessment and short-term treatment centre. Second, to test the hypothesis that adolescent boys are particularly susceptible to suggestions when they are ‘pressured’ by negative feedback and instructions. Finally, to investigate the hypothesis that suggestibility is related to memory recall and self-esteem. The GSS was administered to 31 boys (ages 11 to 16 yr) who had been independently rated by two teachers on measures of suggestibility and self-esteem. Suggestibility as measured by the GSS was found to correlate significantly with the teachers' ratings of suggestibility, supporting empirically the criterion-related validity of the GSS. Compared with young ‘normal’ adults the boys were no more likely to give in to suggestive questions than the adults, unless their performance was subjected to criticism and negative feedback. The results suggest that deliquent adolescents may be particularly responsive to interpersonal pressure during interrogation. The findings have important implications for police interrogation procedures.     

An empirical study of occupational families in the youth labour market

This research aims at identifying job families for use in broadly based training for young people. A total of 455 job incumbents in the youth labour market were interviewed using the Job Components Inventory (JCI). The job sample was heterogeneous, reflecting a wide range of industries and job titles; some of these were skilled but mainly they were semi- and unskilled. The JCI covers the use of tools and equipment, physical and perceptual skills, mathematical requirements, communication, decision making and responsibility. Cluster analysis of items identified 36 skill components. These formed the basis for job-holder profiles, which in turn were grouped by hierarchical clustering. The optimal solution resulted in six clusters, the characteristics of which were described in terms of JCI component scores. The six clusters were labelled as clerical, skilled interpersonal, operative, unskilled manual, intermediate skilled technical and skilled technical. The stability of these six clusters was assessed using split-half replications. Results are discussed and evaluated in the context of contemporary youth training needs.     

Styles of decision making and their use: An empirical study

As interest has increased in teaching decision-making skills, so the need has grown for an empirically-derived classification system of decision-making behaviours. Six styles of decision making were accordingly isolated and validated by content analysis. Using cluster analysis, the styles were found to group into types along a passive-active continuum of involvement in the decision. Use of style was found to vary across situations, and to be related to the decision's perceived importance and the decision-maker's control in the situation.     

Impact of traumatic incidents on family-of-origin functioning: An empirical study

This pilot study was an attempt to empirically validate some of the clinical observations made about traumatic incidents and families in the literature. The study hypothesized that there would be a significant difference in family functioning between those subjects that reported feeling traumatized and those subjects that did not report feeling traumatized, there would be a significant difference in anxiety between the identified trauma group and the identified non-trauma group, and there would be a significant difference in the breadth of support systems between the two groups. The results indicated that there were significant differences between groups of individuals who were identified as traumatized or non-traumatized. The differences included family functioning, individual feelings of anxiety, and report of familial support systems. The findings of this study were congruent with and supportive of much clinical literature on families and traumatic incidents.