Gregor Sočan

The greatest lower bound to the reliability of a test and the hypothesis of unidimensionality

To assess the reliability of congeneric tests, specifically designed reliability measures have been proposed. This paper emphasizes that such measures rely on a unidimensionality hypothesis, which can neither be confirmed nor rejected when there are only three test parts, and will invariably be rejected when there are more than three test parts. Jackson and Agunwambas (1977) greatest lower bound to reliability is proposed instead. Although this bound has a reputation for overestimating the population value when the sample size is small, this is no reason to prefer the unidimensionality-based reliability. Firstly, the sampling bias problem of the glb does not play a role when the number of test parts is small, as is often the case with congeneric measures. Secondly, glb and unidimensionality based reliability are often equal when there are three test parts, and when there are more test parts, their numerical values are still very similar. To the extent that the bias problem of the greatest lower bound does play a role, unidimensionality-based reliability is equally affected. Although unidimensionality and reliability are often thought of as unrelated, this paper shows that, from at least two perspectives, they act as antagonistic concepts. A measure, based on the same framework that led to the greatest lower bound, is discussed for assessing how close is a set of variables to unidimensionality. It is the percentage of common variance that can be explained by a single factor. An empirical example is given to demonstrate the main points of the paper.

Predicting Achievement in Mathematics in Adolescent Students: The Role of Individual and Social Factors

The study examined individual factors and social factors that influence adolescent students’ achievement in mathematics. The predictive model suggested direct positive effects of student intelligence, self-rated openness and parental education on achievement in mathematics, whereas direct effects of extraversion on measures of achievement were negative. Indirect positive effects of intelligence, self-rated conscientiousness, student-perceived mathematics teacher’s press for understanding and mastery goal, and a negative effect of student-rated parental academic pressure on course achievement were mediated through the students’ self-efficacy in mathematics. The findings highlight the important role that individual differences in ability and personality, as well as student perceptions of parent and teacher academically related variables, play in the students’ performance in mathematics.

Relationship between speed of information-processing and two major personality dimensions — Extraversion and neuroticism

Abstract Recent studies show increasing evidence of interdependence of personality traits and mental speed. Probably the most useful theoretical framework for an explanation of these phenomena is offered by the theory of Eysenck [Eysenck, H. J. (1967). The biological basis of personality. Springfield: Charles C. Thomas] of extraversion and neuroticism and by the model of extraversion, proposed by Brebner and Cooper [Brebner, J. (1985). Personality theory and movement. In B. D. Kirkcaldy (Ed.), Individual differences in movement (pp. 27–41). Lancaster: MTP Press.]. The aim of the present study was to test several hypotheses, deduced from the above mentioned theories. Predictions concerned the relationship of several mental speed parameters (e.g. speed and accuracy, variability of performance, decision- and movement-speed) to extraversion, neuroticism and their components. Measures of mental speed included the Hick-Jensen reaction time paradigm, Sternbergs STM scan paradigm, ZVT trail-making test and d2 concentration-endurance test. Extraversion and its components were assessed by means of the 16 Personality Factors questionnaire and the Big Five Questionnaire. In some cases extraversion correlated with speed, but we found no evidence confirming the existence of speed-accuracy trade-off among extraverts and introverts; the correlation between extraversion and mental speed probably depends on the “arousability” of the testing conditions. In some cases extraversion correlated with variability of performance. These results are more conforming to the arousal theory of Eysenck [Eysenck, H. J. (1994). Personality and intelligence: psychometric and experimental approaches. In R. J. Sternberg & P. Ruzgis (Eds.), Personality and intelligence (pp. 3–31). Cambridge: Cambridge University Press than to Brebner and Coopers model of extraversion. Neuroticism correlated negatively with the speed of response; some departures from linearity were also found. No significant correlation with error rate was found. Neuroticism also correlated with variability, whereby the direction of correlation probably depends on measurement conditions.

Consistency in adult reports on child personality over the pre-school years

Three types of temporal and cross-observer consistency in adult reports on child personality were investigated over three waves of a longitudinal study. Employing the Inventory of Child Individual Differences (Halverson et al., 2003), 3-year-olds were rated separately by mothers, fathers, and pre-school teachers. The children were re-assessed one and two years later. The teacher-perceived organization of child personality, which resulted in conscientiousness – openness/intellect, extraversion – emotional stability, and disagreeableness domains appeared stable over time, whereas parental ratings also yielded congruent components across the spouses: extraversion, conscientiousness, disagreeableness, and neuroticism. Mother – father agreement was high across the traits and broadband domains in each wave, while the consistency of the parent – teacher trait assessments was lower. The child scores showed a high rank – order stability and small normative change over the pre-school years. Most of the mean-level change patterns as reflected through adult ratings were similar across the informants, indicating age-increases in extraversion, conscientiousness, and the respective marker traits.

Development and Construct Validation of the Individuation Test for Emerging Adults (ITEA)

This article presents the construction, exploratory dimensionality analysis (Study 1), and validation (Study 2) of the self-report and 36-item Individuation Test for Emerging Adults (ITEA). It is the first instrument to measure different aspects of individuation (in relation to mother and father) specifically in emerging adulthood. The construct validity of the final 5-factor structure (Support Seeking, Connectedness, Intrusiveness, Self-Reliance, and Fear of Disappointing the Parent) was satisfactory. The results of multigroup analyses demonstrated that the factor structure is stable across male and female emerging adults for ITEA assessments in relation to both mother and father. The ITEA scales also show good internal consistency and concurrent validity against Emotional, Conflictual, and Functional Dependence scales of the Psychological Separation Inventory.

A Socio-Cultural Perspective on Children's Early Language: A Family Study.

This study examines the effect of certain socio-cultural factors of the family environment on the language of toddlers and children in early childhood. The sample included 86 families with one- to six-year-old children. The data on the social, economic, and cultural factors of the family environment, parental reading literacy, parental knowledge of childrens development, childrens exposure to shared reading, and child language were obtained in the family environment. Path analysis was used to verify the presumed structural model, which included social and economic factors of the family environment, parental knowledge of childrens development, and parental reading literacy as independent variables, activities used by parents to encourage their childs language as mediating variables, and childrens early literacy and language as a dependent variable. The analysis results showed that the presumed structural model fitted our data well. Parental education (PE), family financial conditions, parental knowledge of childrens development, and parental reading literacy was able to explain 13% of the variance in child language. The obtained results confirm the significant effect of social, economic, and cultural factors of the childs family on language during toddlerhood and early childhood.

Measuring self-care in patients with heart failure: A review of the psychometric properties of the European Heart Failure Self-Care Behaviour Scale (EHFScBS)

OBJECTIVE The aim of this study was to review and evaluate the evidence related to psychometric properties of the European Heart Failure Self-Care Behaviour Scale (EHFScBS) that was developed and tested to measure health maintenance behaviours of heart failure (HF) patients and translated into several languages. METHODS PRISMA guidelines were used to search major health databases (PubMed, Scopus and ScienceDirect), to identify relevant studies. A literature search was undertaken in November 2015. An integrative review, aiming to bring together all evidence relating to the psychometric properties (validity, reliability) of the EHFScBS was conducted. RESULTS 13 eligible studies were included. The results showed content, discriminant and convergent validity of the 9- and 12-item scale across the samples, while the factor structure of both versions of the scale was inconsistent. Most commonly used reliability estimates (Cronbachs alpha) of the total scale were satisfactory. CONCLUSION Overall, published data demonstrate satisfactory psychometric properties of the EHFScBS, indicating that the scale is a reliable and valid tool for measuring health maintenance behaviours of HF patients. PRACTICE IMPLICATIONS Taking the findings regarding the factorial structure of the scale into account, we recommend the use of the total EHFScBS score or scores on specific items.

The set of feasible solutions for reliability and factor analysis.

Abstract The mathematical model underlying factor analysis has the same structure as classical test theory. Both in factor analysis and in test theory, a convex set of “feasible tautologies” has been defined. In factor analysis, the set contains all nonnegative diagonal matrices Ψ of unique variances which entail a reduced covariance matrix σ − Ψ with no negative eigenvalues. In reliability theory, the set contains all non-negative diagonal matrices of error variances which entail a true score covariance matrix with no negative eigenvalues. Points in the feasible set are considered which have direct psychometric interpretations. The most reliable point in test theory has Principal Component Analysis as a factor analysis counterpart. Similarly, the least reliable point, associated with the greatest lower bound to reliability, corresponds to Minimum Trace Factor Analysis. Other factor solutions in the set are Minimum Rank Factor Analysis (minimizing the unexplained common variance for different numbers of retained common factors), and a novel quadratic variant of it. The latter method minimizes the same function as Least Squares Factor Analysis, but does constrain the solution to be in the feasible set. Minimum Rank Factor Analysis solutions have no direct counterparts in test theory, except when only one common factor is extracted. The single factor solution corresponds to the most unidimensional (most congeneric) point in test theory. To evaluate the reliability of congeneric test, the greatest lower bound is argued to be preferable to reliability measures based on a single factor hypothesis. The greatest lower bound is also argued to be superior to reliability based on multiple factor solutions.

Home environment as a predictor of child's language: A mediating role of family literacy activities and symbolic play

In our study, we explored the ways in which SES-related factors of family environment affect childs language across toddlerhood and early childhood. We proposed a mediational path model in which we presumed that family literacy activities and parental encouragement of symbolic play acted as mediating variables, mediating the effect of parental education, family possessions and parent-to-child speech on childs language. The sample included 99 families with children, aged from 1 to 6 years. The data were collected in the family home, mostly via direct observation and by using a semi-structured interview with parents. The findings suggest that high-SES parents and parents who used a more complex and supportive speech, more frequently involved their children in different literacy activities. The effect of the parent-to-child speech on childs language proved to be mediated by parental use of mental transformations during symbolic play with a child.

Analiza notranje strukture slovenske oblike Vprašalnika o sprejemanju bolečine (CPAQ)

V procesu sprejemanja kronicne bolecine se omenja psiholoski koncept sprejemanja, ki vkljucuje izpostavljenost bolecini, ki jo posameznik doživi brez poskusov izogibanja ali nadzora, ter vztrajanje v telesni aktivnosti navkljub prisotnosti bolecine. Na Univerzitetnem rehabilitacijskem institutu Republike Slovenije - Soca (URI - Soca) izvajamo program, v katerem celostno obravnavamo paciente s kronicno razsirjeno bolecino, kjer se prav tako soocamo s pomenom sprejemanja. Za merjenje koncepta sprejemanja uporabljamo Vprasalnik sprejemanja kronicne bolecine (CPAQ, Chronic Pain Acceptance Questionnaire; McCracken idr., 2004), ki smo ga prevzeli iz anglesko govorecega prostora. Namen nase studije je bil za ta instrument preveriti konstruktno veljavnost (prileganje dvofaktorskega modela - delitev 20 postavk v lestvici Pripravljenost na bolecino in Vkljucenost v aktivnost) ter zanesljivost z vidika notranje skladnosti in ponovnega merjenja. V studijo smo vkljucili 241 udeležencev, ki so bili med marcem 2011 in julijem 2013 pregledani v ambulanti za rehabilitacijo oseb s kronicno nerakavo bolecino na URI - Soca. Vsi udeleženci so izpolnili CPAQ. Tako konfirmatorna faktorska analiza kot analiza postavk sta pokazali na neustreznost postavke 16, ki bi jo bilo v prihodnje smiselno opustiti ali preoblikovati. V splosnem se je zanesljivost z vidika notranje skladnosti (obeh lestvic in skupnega dosežka) in vidika ponovnega merjenja izkazala kot ustrezna predvsem za raziskovalne namene.