Background: Despite the widespread use of the Impact of Event Scale to measure post-traumatic stress symptoms, psychometric evaluations of the scale have revealed mixed findings. Aim: The aim of the present study is to provide new empirical evidence and examine the factor structure, reliability, and predictive validity of the Norwegian version of the IES-R. Methods: Posttraumatic stress symptoms were recorded in a student sample (n 0312) 3 weeks after the Southeast Asian tsunami disaster in December 2004. Confirmatory factor analyses of the IES-R behavior items using structural equation modeling (SEM) were performed on four models from existing research. Results: The original three-factor model of intrusion, avoidance and hyperarousal symptoms exhibited the best goodness-of-fit indices when defined as oblique. The IES-R also revealed satisfactory reliability. Symptom levels of intrusion and avoidance were moderate, while hyperarousal scores were low, with a significant gender difference. Conclusion: Taken together, the IES-R revealed good psychometric properties in this nonclinical student sample and could be a useful instrument to assess and follow-up on PTSD symptoms after a certain identified trauma.Gender, IES-R, Media, Psychometric, PTSD, Tsunami.

A Norwegian version of the Penn State Worry Questionnaire (PSWQ) was administered to 304 undergraduate students together with the Beck Depression Inventory (BDI), the State-Trait Anxiety Inventory (STAI) and the Maudsley Obsessive Compulsive Inventory (MOCI). The PSWQ was also administered to a community sample comprising 879 subjects, together with the Beck Anxiety Inventory (BAI), the Beck Depression Inventory II (BDI II) and the White Bear Suppression Inventory (WBSI). Structural equation modeling showed that a three-factor solution of the PSWQ gave the best goodness of fit. The Norwegian version of the PSWQ demonstrated adequate psychometric properties in terms of reliability and validity in both samples. Females scored higher than males on PSWQ.

Modern computer technology permits efficient evaluation of test scores in terms of basic orthogonal factors of ability. A three-level hierarchical model of cognitive abilities was used as the theoretical basis of the computerized Swedish Enlistment Battery (CAT-SEB). Structural analysis of ten ability tests on a sample of 1,436 conscripts by confirmatory factor analysis (tested by the LISREL system) revealed a general, a verbal and a spatial factor ± although the determinacy of the latter was weak. A nested factor model was used, with direct influences of the latent variables on the tests. This result is a construct validity evaluation of the testing system. Unrelated factor scores of the three latent variables comprise the output of the testing system. Future research should evaluate the efficiency of the prediction from the latent variables.

The construct validity of the Swedish Scholastic Test (SweSAT), used for admissions to higher education, was studied through relating it to the Computerized Enlistment Battery (CAT-SEB) used at conscription to military service. Out of three male age cohorts tested at 18 years with the CAT-SEB in 1997, 1998, or 1999 six groups of men that had taken their first SweSAT in the Autumn (n= 3,163; 2,938; 2,820) the same year, or in the Spring (n= 3,238; 2,587; 2,447) the next year were used for the analyses. Four types of models were fitted to the tests: (1) a nested factor model with the latent variables general intelligence (g), crystallized intelligence (Gc) and general visualization; (2) a higher order model with g as an apex factor; (3) a multivariate regression model where the SeSAT subtests were regressed on the SEB factors; and (4) separate models of SweSAT and CAT-SEB with covariances between latent variables. The results show that the SweSAT is dominated by Gc factors and that the g factor has a smaller influence.

Differentiation of cognitive abilities at different levels of general ability in same-aged subjects was tested by a latent variable approach in a multiple-groups design. Eighteen-year old conscripts (n = 14,720) representing the whole range of general ability in the male population, except for the mentally retarded, were tested by the Swedish Enlistment Battery. The sample of subjects was divided into 8, 16 and 32 groups according to level of general ability (G), and the amount of variance due to the ability factors Crystallized intelligence (Gc) and General visualization (Gv) was studied over the G levels. Variance contributed by Gc and Gv increased as the level of G increased. This effect was, however, not observed up through the highest levels of G, probably due to deficiencies in the measurement properties of the Gc and Gv tests at the highest G levels. Theoretical and methodological implications of the results are discussed, as are the consequences for the assessment of specific cognitive abilities at different levels of general ability.