Exploratory Principal Component Analysis Research Articles

Validation of the Arabic Version of the Epworth Sleepiness Scale among the Yemeni Medical Students.

The study was conducted with the aim to assess the psychometric measures of an adapted Arabic version of the Epworth Sleepiness Scale (ESS) among medical students at Sana'a University, Yemen. The cross-sectional study targeted 360 students (males: 176; females: 184) from the preclinical 3rd year (N: 197) and the final clinical year (N: 163). Participants self-filled an Arabic and slightly modified version of the 8-item Epworth Sleepiness Scale. Exploratory Principal Component Analysis (PCA) and Confirmatory Factor Analyses (CFA) were conducted on two equal subsets of the sample (N: 180 each). The PCA yielded a two-dimension model subsequently confirmed by factor analysis. The first dimension was grouped on three items while the second dimension had five items reflecting the respondents' propensity to sleep during “interactive situations” and “sitting and lying,” respectively. The model had an acceptable goodness of fit measures for the overall ESS (CMINDF = 2.362, CFI = 0.91, IFI = 0.92) and acceptable reliability indicators (factor 1 α = 0.65, factor 2 α = 0.62). However, due to weak variance explanation (0.07) of item 6 (sitting and talking) in factor 1, analysis was repeated excluding this item. The 7-item model was also two-dimensional, valid, and reliable. The reliability indicators were acceptable with α = 0.65 for factor 1 (4 items of interactive situations) and 0.62 for factor 2 (3 items of sitting) and overall α = 0.68. Overall, the ESS is a useful tool. Factor analysis produced a two-factor model of 7 items with good validity and reasonable reliability that can be used in diagnosing daytime sleepiness among young Yemeni adults.

Factor Path of Constraints to Adaptive Capacity on Climate Change among IFAD-VCDP Farmers in North Central Nigeria

Aim: Adaptive capacity is the ability of the farmer to adjust his farm plans and programmes in the face of emerging risks, constraints and currently available information. In this study, the various constraints faced by International Fund for Agricultural Development-Value Chain Development Programme’s farmers (IFAD-VCDP) in North Central Nigeria in adapting to climate change challenges were investigated.
 Study Design: A multi-stage sampling technique was employed in the selection of respondents.
 Place and Duration of Study: The study was conducted in Benue and Niger States of Nigeria in 2018.
 Methodology: Data were collected from a total of 483 respondents using interview schedule and questionnaire. The data were analysed using exploratory (principal component analysis) and confirmatory (structural equation modelling) factor analysis.
 Results: The results of the analysis revealed the significant constraints the farmers faced in order to improve their adaptive capacity to climate change which were institutional and technical (49.45%) and climate information (26.62%) constraints, although the factors differ slightly within the two states under study. In Benue State, institutional (31.26%), personal (14.63%), land and farm inputs (12.54%) and population (11.73%) while in Niger State, public and institutional (22.34%), land and farm inputs (14.78%), and personal (10.75) were the constraints to adaptive capacity.
 Conclusion: These constraints make it harder to plan and implement adaptation actions by restricting the variety and effectiveness of options available to the farmers to improve their productivity and cope with the vagaries of climate change. It was therefore recommended that government and NGOs should intensify efforts on public, institutional, educational and climate policies, assist in increasing the adaptive capacity of the farmers in order to employ more adaptation measures, land governance systems should be strengthened in Nigeria to provide tenure security for all, financial institutions should help facilitate access to credit by farmers and assist in making reliable climate information accessible to all farmers.

Intermunicipal healthcare flows and perinatal births and deaths in Greater Metropolitan Rio de Janeiro, Brazil, in 2011 and 2014

The regionalization of perinatal care should consider existing healthcare structures for facilitating access. This spatial-temporal ecological study identified intermunicipal flows of perinatal births and deaths in Greater Metropolitan Rio de Janeiro, Brazil, in 2011 and 2014, defined parameters, and systematized proposals for organizing the regionalization of perinatal care. The data sources were the Brazilian Information System on Live Births, Mortality Information System, National Registry of Healthcare Establishments, and 2010 Population Census. The study identified existing relations between the mothers' municipalities of residence and the occurrence of perinatal births and deaths. Each municipality was analyzed singly and pairwise (residence/occurrence) according to the vital event, healthcare resources, and pragmatic criteria of life-threatening conditions at birth. We conducted descriptive analyses of dominant flows, exploratory principal components analysis, and cluster analysis. The existing healthcare networks were identified, and 47 variables were summarized in three factors (analytical dimensions) - availability of beds, risk of life-threatening conditions, and socioeconomic status - accounting for 60%/80%, 20%/30%, 13%/22%, respectively, of the variance pertaining to each year analyzed. The factors were used to form clusters, classified in 3 to 5 strata. Three proposals were drafted for perinatal health regions. The study's principal contribution was having presented parameters for monitoring the regionalization and systematic reevaluation of this process based on administrative records.

Orientations to Wellbeing in the Context of Medicine and Nursing-A Preliminary Study on Students' Perspective in Their Early University Years.

Medicine in the 21st century needs to be patient-or, rather, person-centered. Accordingly, medical education needs to adopt an authentic student-centered stance and also include an emphasis on wellbeing and quality of life-starting in medical students` university years. Studies on eudaimonic and hedonic aspects of wellbeing in academic contexts might offer valuable insights for conceptualizing and implementing medical teaching. Our research aimed at exploring eudaimonic and hedonic orientations in students in their first years of medical and nursing studies, in relation to outcomes like satisfaction, subjective meaning experience and engagement with university studies. We also wanted to evaluate the feasibility of using a translated version of HEMA (Hedonic and Eudaimonc Motives for Action) Scale in our university students. 120 1st and 2nd year students of our university completed HEMA and questionnaires evaluating the above-mentioned outcomes, in one session. The instrument demonstrated good reliability (assessed by Cronbach`s alpha coefficients) and also captured valuable correlations with students satisfaction, subjective sense of meaning and engagement with their studies. Importantly, eudaimonic subscores were moderately but significantly correlated with Hedonic enjoyment ones, as previously reported. Exploratory Principal Component Analysis suggested two or three factors, but a larger group would be needed to confirm the factor structure of the Romanian version of the test. Conclusions: HEMA is applicable in this academic context, in Romanian, has good reliability and promises to offer valuable insights into students` orientations, helping us support their aspirations and shape our teaching so that they could benefit the most from it.

Whole-genome sequence-based comparison and profiling of virulence-associated genes of Bacillus cereus group isolates from diverse sources in Japan

BackgroundThe complete genome sequences of 44 Bacillus cereus group isolates collected from diverse sources in Japan were analyzed to determine their genetic backgrounds and diversity levels in Japan. Multilocus sequence typing (MLST) and core-genome single-nucleotide polymorphism (SNP) typing data from whole-genome sequences were analyzed to determine genetic diversity levels. Virulence-associated gene profiles were also used to evaluate the genetic backgrounds and relationships among the isolates.ResultsThe 44 B. cereus group isolates, including soil- and animal-derived isolates and isolates recovered from hospitalized patients and food poisoning cases, were genotyped by MLST and core-genome SNP typing. Genetic variation among the isolates was identified by the MLST and core-genome SNP phylogeny comparison against reference strains from countries outside of Japan. Exploratory principal component analysis and nonmetric multidimensional scaling (NMDS) analyses were used to assess the genetic similarities among the isolates using gene presence and absence information and isolate origins as the metadata. A significant correlation was seen between the principal components and the presence of genes encoding hemolysin BL and emetic genetic determinants in B. cereus, and the capsule proteins in B. anthracis. NMDS showed that the cluster of soil isolates overlapped with the cluster comprising animal-derived and clinical isolates.ConclusionsMolecular and epidemiological analyses of B. cereus group isolates in Japan suggest that the soil- and animal-derived bacteria from our study are not a significant risk to human health. However, because several of the clinical isolates share close genetic relationships with the environmental isolates, both molecular and epidemiological surveillance studies could be used effectively to estimate virulence in these important pathogens.

Measuring the urban sustainable development in cities through a Composite Index: The case of Portugal

AbstractThis study aims to systematize indicators and indices that allow measurement sustainable development in cities and towns (economic, social, and environmental). It is one dimension that is inseparable from current cities and its extent is a major concern for political decision‐makers worldwide, and also present their individual weights in that performance. The results allow construction of a Composite Index for Sustainability supported by multivariate statistical techniques (Exploratory Factor Analysis and Principal Component Analysis), confirming its scientific quality and robustness, and forming the main contribution of this study. The results also show that the urban sustainability dimension is visible in the 308 Portuguese cities/towns in a tri‐partite way. Economic sustainability (weighting of 0.386) has been strengthened by entrepreneurship, which has created new business supported by public–private partnerships, such as living labs, which has contributed to less urban unemployment. Standing out in social sustainability (weighting of 0.245) is the development of projects promoting cohesion and social inclusion and actions to improve social infrastructure in Portuguese towns. Finally, environmental sustainability (weighting of 0.369), which locally in Portugal, has emphasized waste management and actions to preserve and protect natural resources and the environment in general. However, more effective actions are needed for their sustainability to continue to improve substantially in the long term, for example, environmentally. Furthermore, the towns/cities analysed must change to the circular economy model as proposed by the European Union.

Dietary patterns and metabolic phenotypes in brazilian adults: a population-based cross-sectional study - ERRATUM.

Objective:Dietary patterns have been pointed out as useful diet quality indicators, but evidence about their relationship to metabolic phenotypes is still scarce. Thus, the present study aimed to verify the relationship between dietary patterns and metabolic phenotypes in Brazilian adults.Design:Cross-sectional study. A food consumption frequency questionnaire assessed food consumption profiles. Metabolic phenotypes were defined based on the criteria of the National Health and Nutrition Examination Survey: overweight or normal weight and metabolically healthy (MHOW and MHNW) or unhealthy (MUOW and MUNW). Dietary patterns were established through exploratory factor analysis and principal component analysis. The associations were tested using multinomial logistic regression.Setting:Vicosa, Minas Gerais, Brazil.Participants:Individuals (n 896) aged 20–59 years of both sexes, selected using probabilistic sampling.Results:Three dietary patterns were identified: Unhealthy pattern (alcoholic beverages, oils and fats, condiments, soda and juice, sugars and sweets, snacks, and meat and derivatives), Traditional pattern (culinary preparations, beans, milk and dairy products, and coffee and tea) and Healthy pattern (vegetables and fruits, whole grains, chicken and fish, and skimmed milk). Unhealthy pattern was positively associated with the MHOW and MUOW phenotypes in the fourth quartile (OR = 1·84; 95 % CI 1·06, 3·22) and in the third (OR = 1·94; 95 % CI 1·11, 3·39) and fourth (OR = 2·56; 95 % CI 1·41, 4·64) quartiles of consumption, respectively. Healthy pattern was also associated with these phenotypes.Conclusions:Both the pattern comprising energy-dense foods and the healthier pattern were associated with overweight phenotypes among Brazilian adults.

Use of near infrared spectroscopy coupled with chemometrics for fast detection of irradiated dry fermented sausages

Chemometric analysis of near infrared (NIR) spectroscopy data was applied to investigate the possibility to rapidly detect dry fermented sausages treated with ionizing radiation at 0; 0,5; 1; 2 and 3 kGy. NIR spectra from 1000 to 2500 nm were subjected to an exploratory principal component analysis (PCA) followed by orthogonal partial last square-discriminant analysis (OPLS-DA) to develop classifiers able to distinguish samples according to the irradiation dose.Models provided a correct classification rate of 100% for both irradiated and non-irradiated specimens. As for the different irradiation doses, 100% of sausages treated at 1 and 3 kGy dose, 92% of those at 2 kGy and 83% of those at 0,5 kGy were correctly classified.The successful results obtained confirmed suitability of chemometric analysis applied to NIR data for fast detection of dry fermented sausages subjected to irradiation treatment.

SOCIAL NETWORK STRENGTHS: AN EXPLORATORY ANALYSIS OF A MEASURE OF TIES AMONG OLDER PEOPLE

Purpose: To explore a self-report measure of social network features among a sample of older people living with multiple chronic conditions based on the conceptual model of Social Network Influences on Health. Design: A cross-sectional descriptive study design using a telephone survey methodology was used. Methods: An exploratory principle component analysis with a varimax rotation was performed on items that measured the identified components (reciprocity, size, proximity, density, general activation, activation when sick, duration, closeness, involvement in health, interaction frequency) of social networks. All items were standardized prior to analyses. Results: Self-report social network data were collected from eighty-four older people living in the community and managing multiple chronic conditions. The principal components model, operationalized as tie strength, contained six items based on factorability: reciprocity, social network size, proximity, density and perception of the activation in general and when sick of close social network members. Results yielded acceptable factorability (KMO = 0.781, Bartlett p 0.70). Two components that had eigenvalues greater than 1.0, explained 61.7% of the total variance. The first factor was interpreted as total social network resources, while the second factor was identified as social network availability. Conclusion: Exploratory principal component analysis supports a measure of social network features, tie strength, that can be tested in future studies. Assessing these variables is useful in identifying specific relationship features critical to managing chronic conditions in older age and advances current measurement of social networks important to living well in older age.

Infrared biomarkers of impaired cystic fibrosis transmembrane regulator protein biogenesis.

The mid-infrared (IR) spectra of human cystic fibrosis (CF) cells acquired by Fourier transform infrared microspectroscopy were compared with those of non-CF cells. Within the 1700 to 1480 cm-1 spectral domain of amides, unsupervised explorative principal component analysis identified a few variables reflecting quantitative and qualitative vibrations arising from protein secondary structures and amino acid side chains. Their pattern reflected α-helix to β-sheet transitions in bronchial epithelial cells and in immortalized peripheral blood mononuclear cells from patients with R1162X missense or in-frame F508del mutations in the cystic fibrosis transmembrane regulator gene (Cftr). Similar transitions have been described in IR spectra of cells, tissues and body fluids of patients affected with some neurodegenerative diseases characterized by the accumulation of misfolded protein aggregates. The variables pattern was able to distinguish CF cells from non-CF cells and was modified by molecular compounds used to rescue the unbalanced folding process of mutated cystic fibrosis transmembrane regulator (CFTR) anion channel. To our knowledge, this is the first experimental evidence of spectroscopic biomarkers of the impaired biogenesis of CFTR by IR microanalysis in the spectra of human CF bronchial epithelial and lymphoblastoid cells.

Rey Tangled Line Test: A measure of processing speed in TBI.

Neuropsychological assessment plays a key role in characterizing and detecting cognitive impairment after traumatic brain injury (TBI). The Rey Tangled Line Test (RTLT), an understudied neuropsychological assessment thought to be capable of detecting visual processing deficits, was examined to determine which cognitive abilities may contribute to performance on the test in participants with a history of TBI. One-hundred participants with a history of mild to severe TBI were administered a battery of neuropsychological tests assessing attention, executive functioning, memory, visual construction, motor functioning, and processing speed between 30 days and 5 years postinjury. An exploratory principal components analysis (PCA) was performed to determine which cognitive tests the RTLT was most highly associated with. No difference in RTLT latency was present between mild and moderate/severe TBI. The PCA resulted in 5 factors. RTLT latency had a significant primary factor loading on the "processing speed" factor, and a secondary loading on the "motor" factor. Forty-two percent of participants had an impaired latency score. RTLT latency appears to measure processing speed, and likely aspects of motor functioning, in our sample. The RTLT may be useful as a rapid assessment in individuals with a history of TBI to detect cognitive deficit before initiating further cognitive testing or rehabilitation efforts. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Dietary patterns and metabolic phenotypes in Brazilian adults: a population-based cross-sectional study.

Dietary patterns have been pointed out as useful diet quality indicators, but evidence about their relationship to metabolic phenotypes is still scarce. Thus, the present study aimed to verify the relationship between dietary patterns and metabolic phenotypes in Brazilian adults. Cross-sectional study. A food consumption frequency questionnaire assessed food consumption profiles. Metabolic phenotypes were defined based on the criteria of the National Health and Nutrition Examination Survey: overweight or normal weight and metabolically healthy (MHOW and MHNW) or unhealthy (MUOW and MUNW). Dietary patterns were established through exploratory factor analysis and principal component analysis. The associations were tested using multinomial logistic regression. Viçosa, Minas Gerais, Brazil. Individuals (n896) aged 20-59 years of both sexes, selected using probabilistic sampling. Three dietary patterns were identified: Unhealthy pattern (alcoholic beverages, oils and fats, condiments, soda and juice, sugars and sweets, snacks, and meat and derivatives), Traditional pattern (culinary preparations, beans, milk and dairy products, and coffee and tea) and Healthy pattern (vegetables and fruits, whole grains, chicken and fish, and skimmed milk). Unhealthy pattern was positively associated with the MHOW and MUOW phenotypes in the fourth quartile (OR = 1·84; 95 % CI 1·06, 3·22) and in the third (OR = 1·94; 95 % CI 1·11, 3·39) and fourth (OR = 2·56; 95 % CI 1·41, 4·64) quartiles of consumption, respectively. Healthy pattern was also associated with these phenotypes. Both the pattern comprising energy-dense foods and the healthier pattern were associated with overweight phenotypes among Brazilian adults.

Chemometrics-enhanced Classification of Source Rock Samples Using their Bulk Geochemical Data: Southern Persian Gulf Basin

Chemometric methods can enhance geochemical interpretations, especially when working with large datasets. With this aim, exploratory hierarchical cluster analysis (HCA) and principal component analysis (PCA) methods are used herein to study the bulk pyrolysis parameters of 534 samples from the Persian Gulf basin. These methods are powerful techniques for identifying the patterns of variations in multivariate datasets and reducing their dimensionality. By adopting a “divide-and-conquer” approach, the existing dataset could be separated into sample groupings at family and subfamily levels. The geochemical characteristics of each category were defined based on loadings and scores plots. This procedure greatly assisted the identification of key source rock levels in the stratigraphic column of the study area and highlighted the future research needs for source rock analysis in the Persian Gulf basin.

Subsidized housing and geographic accessibility to neighborhood resources for low-income older people: From later year social exclusion perspective

ObjectivesDrawing on the perspective of later year social exclusion, this study (1) assessed geographic accessibility to health and social services in subsidized senior housing in Chicago. (2) examined the association between senior housing's accessibility to health/social services, and social exclusion at the neighborhood level. MethodsFirst, senior housing and social/health services data were geocoded and spatially merged with all accessible streets/roads in Chicago area. Second, using network analysis, an advanced GIS technique, we compared degree of accessibility based on the standardized distribution of health and social resources. Third, to examine social exclusion at a neighborhood level, we conducted an exploratory principal component analysis (PCA) to construct a composite score of social exclusion. Last, we ran bivariate analyses (ANOVA) to examine the association between service accessibility and social exclusion components. ResultsThere were 102 subsidized senior housing facilities, surrounded by 120 health service agencies and social services, including 80 libraries, 21 senior centers, and 28 family and support services. PCA analysis revealed five components from the original 16 social exclusion indicators: socio-economic disadvantage, low social integration, environmental hazard, lack of service availability marginalization. The socio-health accessibility was significantly related to two social exclusion factors: socio-economic disadvantage and low social integration. DiscussionAs the first study based on a geospatial approach that focuses on subsidized senior housing's accessibility neighborhood resources, our findings showed that subsidized senior housing not only has differential levels of service, but more importantly is embedded in a qualitatively different nature of social exclusion at neighborhood level.

Identifying culturally acceptable cognitive tests for use in remote northern Australia

BackgroundA lack of culturally appropriate tests hampers accurate assessment of cognition in remote Australian Aboriginal communities. In Arnhem Land, this study employed a community consultation process to evaluate commonly used Western tests of executive function, memory, attention, and visuospatial function.MethodsAn initial consultation process and a follow-up pilot study resulted in the rejection of some common tests, the development of new tests, and culturally adapted versions of others. In the subsequent 30-person main trial, adult Aboriginal volunteers were examined on nine tests, plus the Kimberly Indigenous Cognitive Assessment screen, and a brief literacy test.ResultsExecutive function, memory, and attention tests were found to group separately after an exploratory principal components analysis. Correlations between new tests and similar Kimberly screen items were not significant, but ceiling effects may be relevant. Six of 13 test scores were found to correlate with the literacy measure.ConclusionsA selection of cognitive tests were identified that Aboriginal people found culturally acceptable and engaging. In particular, Self-Ordered Pointing, Trail-Making, a verbal-switching task, and a new test “Which car?” show promise for further development. This work may contribute to the need for culturally appropriate cognitive testing in Aboriginal communities.

Construction and validation of a public bus passenger safety scale

Public transport (PT) passengers make safety evaluations, yet to the best of our knowledge, there exists no instrument that captures what is considered by public transport users when they make such personal safety evaluations. What exists is a generalised service quality scale (SERVQUAL). Unfortunately, this scale does not adequately capture the content domain of personal safety which is important to PT users, especially in developing countries where PT vehicle accidents are both frequent and severe. This study discusses the development and validation of a public bus passenger safety scale (PBPSS), for measuring public bus passengers’ safety. The results of two independent studies suggest that the PBPSS measures three facets of public bus passengers’ safety: driver-related, transport operator-related and vehicle-related. Through both exploratory Principal Component Analysis (PCA) and Confirmatory Factor Analysis (CFA) (using IBM SPSS Statistics and AMOS respectively), we demonstrated that the new scale is reliable, psychometrically sound and can be utilised to assess public bus passengers’ safety. The 3-factor model observed through PCA was confirmed using CFA, indicating that the same factor structure existed in both datasets. The final 3-factor, 17-item model exhibited an acceptable model fit and evidenced both convergent and discriminant validity.

The development and psychometric testing of the Perinatal Infant Care Social Support (PICSS) instrument

BackgroundSocial support facilitates a woman's transition to motherhood. This major developmental transition can be stressful as it includes adaptation of self as well as learning new infant care practice skills. Although a number of instruments have been developed to measure social support, none have been developed or underpinned by theory in the context of perinatal infant care practices. AimTo develop a reliable and valid instrument to measure social support for new mothers in the perinatal period. MethodsPhase 1 involved the development of instrument structure and content. Constructs to be measured were defined through an analysis of relevant theoretical and empirical literature.Phase 2 established the psychometric properties of the functional domain of the PICSS. Exploratory factor analyses and principal Component Analyses were undertaken with a sample of first-time mothers (n = 371) from postnatal wards of a large maternity hospital. Item reduction and Cronbach's alpha reliability tests were performed. The structural social support domain was not amenable to psychometric testing. ResultsExploratory Factor Analyses and Principal Component Analyses of the functional domain resulted in a logically coherent 19-item, two-factor solution. The first factor ‘Supporting Presence’ has nine items (Cronbach's alpha = 0.90) and the second factor ‘Practical Support’ has ten items (Cronbach's alpha = 0.86). ConclusionsThe PICSS is a coherent and valid measure of social support for new mothers in the postnatal period in the context of infant care practices.

Psychosocial wellbeing among new mothers with diabetes: Exploratory analysis of the postnatal wellbeing in transition questionnaire

ObjectiveThe Postnatal Wellbeing in Transition (PostTrans) Questionnaire assesses psychosocial wellbeing among women transitioning to motherhood while managing pre-existing diabetes. Face and content validity have been previously reported; however the PostTrans questionnaire has 51 items which imposes a substantial burden on respondents. The aim of this study was exploratory analysis of the PostTrans questionnaire to investigate whether a reduction in the number of items was statistically supported, and whether clinically meaningful subscales could be derived. MethodsA prospective cohort of women with type 1 or type 2 diabetes was recruited from three metropolitan hospitals in Melbourne, Australia. Women completed surveys across three postnatal time points. Data were pooled for the analysis. Suitability for factor analysis was confirmed and exploratory Principal Components Analysis with oblique rotation was conducted. ResultsThe number of responses in the pooled dataset was 117. The reduced PostTrans scale has 27 items and six factors, which together explain 68.7% of the variance. The subscales assess: feeling as if one is coping with diabetes and the infant; feeling anxious and guilty about diabetes; feeling supported by family; sensitivity to the opinions of others; prioritising self-care; and health professional support. ConclusionThe number of items in the PostTrans Questionnaire was reduced from 51 to 27 items. Six meaningful subscales emerged, which can help health professionals identify and address areas in which women with diabetes are experiencing psychosocial difficulties. The revised scale provides a feasible instrument to be tested for psychometric properties in a larger sample.

A-52 An Exploratory Factor Analysis Investigation of the Role of Verbal Mediation in the Interaction between Intelligence and Visual Memory Tasks

Abstract Objective Examine whether verbal mediation may play a role in the interaction between visual memory tasks and the four-factor model of intelligence as operationalized by standard neuropsychological assessment instruments. Method The assessment records of 101 American Veterans with diverse neuropsychiatric conditions were examined using Exploratory Factor and Principal Component Analyses (EFA and PCA respectively). There were no exclusion criteria. All participants completed the Wechsler Adult Intelligence Scale, third edition (WAIS-III), Benton’s Visual Retention Test (BVRT), and Multilingual Aphasia Examination (MAE). Individual assessment instruments were factored using PCA. The factor solution of the BVRT was co-factored with the scales of the WAIS-III, then the resulting factor scales were again factored with the verbal components of the MAE to identify common sources of variance. Results A three-step analysis revealed a four-factor model explaining 69.44% of the shared variance: 1) Items 1-4 of the BVRT (BVRT-E) loaded with Verbal Comprehension and Visual Naming. 2) BVRT-E also loaded with Processing Speed and Controlled Word Association. 3) Items 5-10 of the BVRT (BVRT-L) loaded with Perceptual Organization and the Token Test. 4) Working Memory loaded with Sentence Repetition on a fourth factor. Conclusions The results indicate a strong relationship between assessed performance on visual memory tasks and performance on measures based on the four-factor model of intelligence. The results also appear to support the idea that verbal mediation plays a role in the interaction between visual memory and intelligence, particularly when comparing performance on simple versus more complex visual memory tasks.

A Primer to (Cross-Cultural) Multi-Group Invariance Testing Possibilities in R.

Psychology has become less WEIRD in recent years, marking progress toward becoming a truly global psychology. However, this increase in cultural diversity is not matched by greater attention to cultural biases in research. A significant challenge in culture-comparative research in psychology is that any comparisons are open to possible item bias and non-invariance. Unfortunately, many psychologists are not aware of problems and their implications, and do not know how to best test for invariance in their data. We provide a general introduction to invariance testing and a tutorial of three major classes of techniques that can be easily implemented in the free software and statistical language R. Specifically, we describe (1) confirmatory and multi-group confirmatory factor analysis, with extension to exploratory structural equation modeling, and multi-group alignment; (2) iterative hybrid logistic regression as well as (3) exploratory factor analysis and principal component analysis with Procrustes rotation. We pay specific attention to effect size measures of item biases and differential item function. Code in R is provided in the main text and online (see https://osf.io/agr5e/), and more extended code and a general introduction to R are available in the Supplementary Materials.