On the dimensionality of the System Usability Scale: a test of alternative measurement models

The System Usability Scale (SUS), developed by Brooke (Usability evaluation in industry, Taylor & Francis, London, pp 189–194, 1996), had a great success among usability practitioners since it is a quick and easy to use measure for collecting users’ usability evaluation of a system. Recently, Lewis and Sauro (Proceedings of the human computer interaction international conference (HCII 2009), San Diego CA, USA, 2009) have proposed a two-factor structure—Usability (8 items) and Learnability (2 items)—suggesting that practitioners might take advantage of these new factors to extract additional information from SUS data. In order to verify the dimensionality in the SUS’ two-component structure, we estimated the parameters and tested with a structural equation model the SUS structure on a sample of 196 university users. Our data indicated that both the unidimensional model and the two-factor model with uncorrelated factors proposed by Lewis and Sauro (Proceedings of the human computer interaction international conference (HCII 2009), San Diego CA, USA, 2009) had a not satisfactory fit to the data. We thus released the hypothesis that Usability and Learnability are independent components of SUS ratings and tested a less restrictive model with correlated factors. This model not only yielded a good fit to the data, but it was also significantly more appropriate to represent the structure of SUS ratings.

Reciprocal relationships between job resources, personal resources, and work engagement

This study examined longitudinal relationships between job resources, personal resources, and work engagement. On the basis of Conservation of Resources theory, we hypothesized that job resources, personal resources, and work engagement are reciprocal over time. The study was conducted among 163 employees, who were followed-up over a period of 18 months on average. Results of structural equation modeling analyses supported our hypotheses. Specifically, we found that T1 job and personal resources related positively to T2 work engagement. Additionally, T1 work engagement related positively to T2 job and personal resources. The model that fit best was the reciprocal model, which showed that not only resources and work engagement but also job and personal resources were mutually related. These findings support the assumption of Conservation of Resources theory that various types of resources and well-being evolve into a cycle that determines employees’ successful adaptation to their work environments.     

Psychological and demographic correlates of career patterns

Recent years have witnessed a growing diversity of career patterns, resulting from the relative decline of stable employment. In the present study of 1368 employed and self-employed German adults career pattern diversity was assessed using nine pictograms. The goal was to identify psychological and demographic correlates of these patterns and to answer the question of whether they differed for participants from the former (communist) East and the capitalist West. Findings indicated that upward-pointing career patterns still connected to extrinsic criteria such as income and job security. With regard to psychological correlates, upward patterns connected to lower work-related demands imposed by social change and a higher level of personal and social resources. Only in the West, upward patterns related to male gender and high education, reflecting more traditional access to upwardly mobile career opportunities.     

Personality types and self-reported aggressiveness

Applying a person-centered approach, three personality types based on the NEO-FFI scales were identified in a sample of N = 141 participants by means of clustering methods. They were described as a resilient (low N, high E), a non-desirable (high N, low E, A, and C), and a reserved overcontrolled prototype (low E and O, high A and C). The prototypes were related to the level of aggressiveness, assessed by the Buss–Perry Aggression Questionnaire (AQ). Results indicate that the three clusters differ mainly in their levels of hostility, verbal aggressiveness, and with respect to anger. With respect to total aggressiveness, the non-desirable prototype displayed the highest and the reserved prototype the lowest AQ scores. The results are discussed in relation to studies based on a variable-centered approach. Possible implications for treatment and research are addressed.     

Ethical and methodological aspects of medical computer data bases and knowledge bases

Ethical problems are related to computer data bases, containing data on individuals and groups of persons, as well as to computer knowledge bases, containing general rules and elements of expert systems.In the present essay the following conclusions are made regarding computer data bases: privacy, security, and confidentiality of medical computer data bases should be ensured. This duty should rest with physicians in hospitals. The principle of informed consent should be applied to gathering information which is to be stored and processed by computers. Information stored in computer data bases should not be used for purposes for which the subjects (patients as well as personnel) have not given their consent. In order to decrease the possibility of misuses of medical data bases containing information on individuals, these registers should not be linked to other central data bases.     

Personal Identity, Fission and Time Travel

One problem that has formed the focus of much recent discussion on personal identity is the Fission Problem. The aim of this paper is to offer a novel solution to this problem.

The Enhanced Agentic Diversity Perspective (EADP): An appeal for Co-creating an accommodative social space so that diversity unlocks innovativeness rather than problems

We propose in this article an Enhanced Agentic Diversity Perspective (EADP), which is derived from the concept of agentic resources in social relational theory. EADP recognizes that all human beings are equally agents, that agentic expressions differ due to variation of individual access to power resources (individual, relational and cultural) and that the current social conditions serve to promote agentic diversity by enhancing all the three domains of power resources. In addition, EADP comprises a proposal for the development of accommodative social spaces. We argue that only in an accommodative social space can diversity unlock innovation; otherwise, it serves as a source for conflict. A constructive, nonhierarchical account of diversity, such as EADP is needed under current social conditions for the optimal becoming of idiosyncratic human agents as well as human society as a whole.     

Struggling with self: The personal projects of students seeking psychological counselling

Personal projects can be described as self-articulated goals and related sequences of actions. In order to investigate what kind of personal projects people with psychological problems have, and how they work on them, 28 counselling client students, 44 students of psychology, and 45 students of technology completed a Finnish version of Little's (1987) Personal Project Inventory. The results showed that the clients scored lower on project accomplishment than other groups. Their personal projects were frequently self-related, while those of the technology students were often task-related. The higher their sense of coherence, self-esteem, mental health and life satisfaction, the more subjects expected to accomplish their projects, the more frequently they described task-related projects, the less negative affect they reported, and the less frequently they described self-related projects. These results suggest that psychologically distressed individuals struggle with self-related projects and have problems in accomplishing their projects.     

The cognitive-somatic anxiety questionnaire: Psychometric and validity data

The Cognitive-Somatic Anxiety Questionnaire (CSAQ) is a 14-item self-report inventory that is divided into two 7-item scales (Cognitive and Somatic) that appear to reflect cognitive or somatic anxiety. In an attempt to evaluate the construct validity of this multidimensional instrument, the CSAQ was administered to 109 college students along with several other measures of physical and psychological symptoms. The results suggest that (a) despite considerable overlap between the Cognitive and the Somatic scales (r=.62), an exploratory factor analysis is able to identify a single large somatic factor along with three lesser cognitive-appearing factors, and (b) the correlations with concurrent measures of related constructs provide some limited evidence of the construct validity of the CSAQ. For males, both the Cognitive and the Somatic scales of the CSAQ correlated significantly with several anxietyrelated measures. However, for females CSAQ scores correlated less consistently with the other test scales, although Somatic scale scores for females were positively related to measures of health and exercise involvement. Suggestions for improving the CSAQ are offered.