Multidimensional or essentially unidimensional? A multi-faceted factor-analytic approach for assessing the dimensionality of tests and items.

Background: Factor-analysis based dimensional assessment of psychometric measures is a key step in the development of tests. However, current practices for deciding between a multiple-correlated or essentially unidimensional solution are clearly improvable.

Method: A series of recent studies are reviewed, and an approach is proposed that combines multiple sources of information, which is expected to be used to make an informed judgement about the most appropriate dimensionality for the measure being studied.

Distortions and gender-related differences in the perception of mechanical engineering in high school students.

Background: The reason for this study was the low interest that high school students, particularly females, show for the subject of mechanical engineering (ME). We assumed that this problem was partly due to: (a) lack of understanding of the tasks involved in ME, and (b) a distorted and negative perception of the professional environment and working conditions.

Method: To assess these two assumptions, two measurement instruments (tasks and perceptions) were developed and administered in a sample of 496 high school students.

[Assessment of individual differences in faking].

In recent years, change scores obtained under neutral conditions and under faking-inducing conditions have become one of the main alternatives for operationalizing faking. A pending issue regarding these measures is the relevance of individual differences under similar conditions of pressure. This study proposes a simple approach based on the classic test theory that allows the issue to be rigorously assessed.

[Assessment of depressive symptoms in old visually-impaired people: a study of the Geriatric Depression Scale].

This study has two main purposes: (a) to assess the functioning of the Geriatric Depression Scale in its Spanish version in old visually-impaired people, and (b) to assess the relevance of measuring depressive symptoms within a comprehensive assessment of psychological adjustment related to vision impairment in that population. Respondents were 329 people affiliated to the ONCE who were a representative sample of the target population. The assessment of the first goal let us to establish two cut-off points, and led to new methodological developments that combine Item Response Theory and Classical Test Theory.

[Graphical procedures for assessing person-fit in item factor analysis].

Flagging the individuals who did not answer consistently can be very useful in certain applied domains, especially in clinical and personnel selection areas. Identification of inconsistent patterns prevents erroneous interpretations of test scores. Two graphic procedures based on linear factor analysis are proposed in this paper.

[Implementing graphical and analytical procedures for developing parallel tests].

We present an instrumental study in which two general procedures (graphical and objective) for constructing parallel forms are implemented. Both procedures are based on an item pool which is calibrated by means of the classical test theory. The graphic procedure is Gulliksen's matched random subtests method.

[Content and form characteristics that predict discriminating power in personality items: an item response theory-based analysis].

In two personality item pools that measure extraversion and neuroticism, the relations between three groups of itemmetric properties and the estimated discrimination indexes according to the two-parameter model are assessed. The itemmetric properties, which are conceptualized as dimensions, are: verbal complexity, ambiguity, and trait indicativity, and the hypotheses concerning their impact on the discriminating power are derived from a processing-stage model. The dimension of trait indicativity shows the clearest relations with the discriminating power in the expected direction.

[Cognitive and affective variables as predictors of life satisfaction].

This work shows the association between personality variables, such as cognitive and affective variables, and psychological adjustment, such as life satisfaction and depressive symptoms. Accordingly, this study assessed the role of outcome expectancies (optimism and pessimism) and affectivity (positive and negative affect) as a predictors of life satisfaction and depressive symptoms. A total of 458 students from the University Rovira i Virgili completed the scales LOT-R, PANAS, the Satisfaction with Life Scale and BDI.