A Short Version of the Big Five Inventory (BFI-20): Evidence on Construct Validity

Several measures were developed in the past decades to measure personality, focusing on the Big Five Factor Model (BFFM; Openness, Conscientiousness, Extraversion, Agreeableness, and Neuroticism). Despite the relevance of their findings in different countries, a shared limitation of such measures is their length, demanding time from researchers and participants, which might cause boredom or fatigue, biasing the final results. This research aimed to provide a shorter version for the 44-Item Big Five Inventory (BFI), through two studies (NTotal = 8,119). The structure was assessed using a range of techniques (e.g., PAF analysis, Procrustes rotation). The best 20 items (4 per factor) were chosen to compose the final version of the BFI-20, which presented suitable psychometric evidences across the samples. Thus, due the growing need for shorter measures without losing their psychometric quality, our findings indicate the adequacy of the 20-item BFI and its potential applicability in research context.

Determining the orientation of marine CSEM receivers using orthogonal Procrustes rotation analysis

Electromagnetic receivers deployed to the seafloor for CSEM surveys can have unknown orientations because of the unavailability of compass and tilt recordings. In such situations, only the orientation-independent parameters derived from the measured CSEM field vector can be interpreted, and this may result in less structural resolution than possible when the sensor orientations are known. An orthogonal Procrustes rotation analysis (OPRA) technique can be used to estimate the full 3D receiver orientation for inline and off-line CSEM receivers. The generality of this method allows it to be easily embedded into nonlinear CSEM inversion routines so that they iteratively search for both the receiver orientation and a seafloor electrical-conductivity model compatible with the data. Synthetic tests using the OPRA method jointly with a 1D inversion demonstrate that it can recover the rotation and tilt angles to about one degree accuracy for 1D data and to within a few degrees for 2D data. Application of this method to real survey data shows good agreement with a previous orientation method that is suitable only for determining the horizontal rotation of inline receivers. CSEM data collected over the Pluto gas field offshore the northwest coast of Australia were used to demonstrate how the OPRA method can be used to orient CSEM receivers prior to inversion of only the inline electric- and crossline magnetic-field components.

Using exploratory factor analysis in personality research: Best-practice recommendations

Orientation: Exploratory factor analysis is the method of choice with objective personality instruments, particularly to establish the construct validity and construct equivalence of trait-based instruments.Research purpose: This article presents more objective methods to determine the number of factors, most notably parallel analysis and Velicer’s minimum average partial (MAP). The benefits of rotation are also discussed. The article argues for more consistent use of Procrustes rotation and congruence coefficients in factor analytic studies.Motivation for the study: Exploratory factor analysis is often criticised for not being rigorous and objective enough in terms of the methods used to determine the number of factors, the rotations to be used and ultimately the validity of the factor structure.Research design, approach and method: The article adopts a theoretical stance to discuss the best-practice recommendations for factor analytic research in the field of psychology. Following this, an example located within personality assessment and using the NEO-PI-R specifically is presented. A total of 425 students at the University of the Witwatersrand completed the NEO-PI-R. These responses were subjected to a principal components analysis using varimax rotation. The rotated solution was subjected to a Procrustes rotation with Costa and McCrae’s (1992) matrix as the target matrix. Congruence coefficients were also computed.Main findings: The example indicates the use of the methods recommended in the article and demonstrates an objective way of determining the number of factors. It also provides an example of Procrustes rotation with coefficients of agreement as an indication of how factor analytic results may be presented more rigorously in local research.Practical/managerial implications: It is hoped that the recommendations in this article will have best-practice implications for both researchers and practitioners in the field who employ factor analysis regularly.Contribution/value-add: This article will prove useful to all researchers employing factor analysis and has the potential to set the trend for better use of factor analysis in the South African context.