The multilevel latent covariate model: a new, more reliable approach to group-level effects in contextual studies

In multilevel modeling (MLM), group-level (L2) characteristics are often measured by aggregating individual-level (L1) characteristics within each group so as to assess contextual effects (e.g., group-average effects of socioeconomic status, achievement, climate). Most previous applications have used a multilevel manifest covariate (MMC) approach, in which the observed (manifest) group mean is assumed to be perfectly reliable. This article demonstrates mathematically and with simulation results that this MMC approach can result in substantially biased estimates of contextual effects and can substantially underestimate the associated standard errors, depending on the number of L1 individuals per group, the number of groups, the intraclass correlation, the sampling ratio (the percentage of cases within each group sampled), and the nature of the data. To address this pervasive problem, the authors introduce a new multilevel latent covariate (MLC) approach that corrects for unreliability at L2 and results in unbiased estimates of L2 constructs under appropriate conditions. However, under some circumstances when the sampling ratio approaches 100%, the MMC approach provides more accurate estimates. Based on 3 simulations and 2 real-data applications, the authors evaluate the MMC and MLC approaches and suggest when researchers should most appropriately use one, the other, or a combination of both approaches.     

Cognitive interference and aging: insights from a spatial stimulus-response consistency task

One hundred and thirty-one adults belonging to four age groups (19-26, 50-59, 60-69 and 70-82 years) performed a spatial stimulus-response consistency task in which the response dimension (left or right) overlapped relevant and irrelevant stimulus dimensions. The influence of the irrelevant stimulus dimension on response time was significantly greater in the middle age groups than among 19-26 year-olds, and significantly greater in the highest age group than in any other. This pattern persisted when allowance was made for a significant age-related increase in processing time (measured as reaction time in a single-stimulus, single-response task). It is concluded that in tasks of the kind used, the elderly resist interference from the irrelevant information less easily than do younger persons. Interestingly, comparison of Vincentized quintiles suggested that the effect of the irrelevant stimulus dimension decreased with increasing response time among 19-26 year-olds, but increased with response time among 70-82 year-olds.     

Incorporating randomness in the Fisher information for improving item‐exposure control in CATs

The most commonly employed item selection rule in a computerized adaptive test (CAT) is that of selecting the item with the maximum Fisher information for the estimated trait level. This means a highly unbalanced distribution of item‐exposure rates, a high overlap rate among examinees and, for item bank management, strong pressure to replace items with a high discrimination parameter in the bank. An alternative for mitigating these problems involves, at the beginning of the test, basing item selection mainly on randomness. As the test progresses, the weight of information in the selection increases. In the present work we study, for two selection rules, the progressive methods ( Revuelta & Ponsoda, 1998 ) and the proportional method ( Segall, 2004a ), different functions that define the weight of the random component according to the position in the test of the item to be administered. The functions were tested in simulated item banks and in an operative bank. We found that both the progressive and the proportional methods tolerate a high weight of the random component with minimal or zero loss of accuracy, while bank security and maintenance are improved.     

Songs as an aid for language acquisition

In previous research, Saffran and colleagues [Saffran, J. R., Aslin, R. N., & Newport, E. L. (1996). Statistical learning by 8-month-old infants. Science, 274, 1926-1928; Saffran, J. R., Newport, E. L., & Aslin, R. N. (1996). Word segmentation: The role of distributional cues. Journal of Memory and Language, 35, 606-621.] have shown that adults and infants can use the statistical properties of syllable sequences to extract words from continuous speech. They also showed that a similar learning mechanism operates with musical stimuli [Saffran, J. R., Johnson, R. E. K., Aslin, N., & Newport, E. L. (1999). Abstract Statistical learning of tone sequences by human infants and adults. Cognition, 70, 27-52.]. In this work we combined linguistic and musical information and we compared language learning based on speech sequences to language learning based on sung sequences. We hypothesized that, compared to speech sequences, a consistent mapping of linguistic and musical information would enhance learning. Results confirmed the hypothesis showing a strong learning facilitation of song compared to speech. Most importantly, the present results show that learning a new language, especially in the first learning phase wherein one needs to segment new words, may largely benefit of the motivational and structuring properties of music in song.     

Psychological differences of patients and relatives according to post-transplantation anxiety

The aim of this investigation is to analyze the psychological differences of patients and their relatives according to the formers' post-transplantation anxiety. We used two groups of participants: transplant patients (n = 166) and close relatives (n = 166). Four questionnaires were applied: a Psychological Survey (to both groups), the Hospital Anxiety and Depression Scale, and the Quality of Life Questionnaire (to the transplant patients), and the Leeds Scales for the Self-Assessment of Anxiety and Depression (to the relatives). Participants were assessed twice: post-Intensive Care Unit (ICU; when patients were moved from the ICU to the Transplantation Unit) and post-hospital (one year after transplant). Results showed that high anxiety in patients just after organ transplant was related to an increase of anxiety and depression symptoms both in patients and relatives one year after transplant; it was also related to a decrease in the quality of life of these patients.     

Evidence for linguistic deficit in nonlexical processing in reading. A study of a Spanish-speaking patient

Previous studies have shown that in the so-called opaque languages (those in which spelling does not correspond to pronunciation), there are relatively independent routes for lexical and nonlexical processing, that is, for words and nonwords, both in spoken and in written language. On the other hand, in the so-called transparent languages (those in which pronunciation corresponds to written forms), empirical evidence is scarcer. In this study of a neurological patient (parieto-temporal lesion), speaker of a transparent language (Spanish) showing a specific deficit in nonlexical reading processing, linguistic analysis for words was relatively preserved. This finding suggests the use of various routes in the processing of transparent languages.     

Psychometric properties of a Spanish version of the Beck Anxiety Inventory (BAI) in general population

This is the first study that provides normative, reliability, factor validity and discriminant validity data of the Beck Anxiety Inventory (BAI; Beck, Epstein, Brown, & Steer, 1988) in the Spanish general population, Sanz and Navarro's (2003) Spanish version of the BAI was administered to 249 adults. Factor analyses suggested that the BAI taps a general anxiety dimension comprising two related factors (somatic and affective-cognitive symptoms), but these factors hardly explained any additional variance and, therefore, little information is lost in considering only full-scale scores. Internal consistency estimate for the BAI was high (alpha = .93). The BAI was correlated .63 with the BDI-II and .32 with the Trait-Anger scale of the STAXI 2, but a factor analysis of their items revealed three factors, suggesting that the correlations between the instruments may be better accounted for by relationships between anxiety, depression, and anger, than by problems of discriminant validity. The mean BAI total score and the distribution of BAI scores were similar to those found in other countries. BAI norm scores for the community sample were provided from the total sample and from the male and female subsamples, as females scored higher than males. The utility of these scores for assessing clinical significance of treatment outcomes for anxiety is discussed.     

A measure of racial identity in African American adolescents: the development of the Multidimensional Inventory of Black Identity--Teen

The Multidimensional Inventory of Black Identity--Teen (MIBI--T) is designed to assess the 3 cross-situationally stable dimensions (centrality, regard, and ideology) of the Multidimensional Model of Racial Identity (MMRI; R. M. Sellers, M. A. Smith, J. N. Shelton, S. A. J. Rowley, & T. M. Chavous, 1998) within teenagers. Adolescent responses (n= 489) to the MIBI--T were subjected to several analyses to evaluate the psychometric character of the measure. Findings indicated that the MIBI--T represents a valid framework for African American adolescents. Its internal structure is consistent with the conceptual framework of the MMRI, and findings support its construct validity. Results also indicate model invariance across grade level and gender, as well as suggest evidence of predictive validity. Further information about the MIBI--T and the full set of items are presented.     

Elucidating the component processes involved in dyslexic and non-dyslexic reading fluency: An eye-tracking study

The relationship between rapid automatized naming (RAN) and reading fluency is well documented (see Wolf, M. & Bowers, P.G. (1999). The double-deficit hypothesis for the developmental dyslexias. Journal of Educational Psychology, 91(3), 415–438, for a review), but little is known about which component processes are important in RAN, and why developmental dyslexics show longer latencies on these tasks. Researchers disagree as to whether these delays are caused by impaired phonological processing or whether extra-phonological processes also play a role (e.g., Clarke, P., Hulme, C., & Snowling, M. (2005). Individual differences in RAN and reading: A response timing analysis. Journal of Research in Reading, 28(2), 73–86; Wolf, M., Bowers, P.G., & Biddle, K. (2000). Naming-speed processes, timing, and reading: A conceptual review. Journal of learning disabilities, 33(4), 387–407). We conducted an eye-tracking study that manipulated phonological and visual information (as representative of extra-phonological processes) in RAN. Results from linear mixed (LME) effects analyses showed that both phonological and visual processes influence naming-speed for both dyslexic and non-dyslexic groups, but the influence on dyslexic readers is greater. Moreover, dyslexic readers’ difficulties in these domains primarily emerge in a measure that explicitly includes the production phase of naming. This study elucidates processes underpinning RAN performance in non-dyslexic readers and pinpoints areas of difficulty for dyslexic readers. We discuss these findings with reference to phonological and extra-phonological hypotheses of naming-speed deficits.     

Perceptual-cognitive skills and performance in orienteering

The goal was analysis of the perceptual-cognitive skills associated with sport performance in orienteering in a sample of 22 elite and 17 nonelite runners. Variables considered were memory, basic orienteering techniques, map reading, symbol knowledge, map-terrain-map identification, and spatial organisation. A computerised questionnaire was developed to measure the variables. The reliability of the test (agreement between experts) was 90%. Findings suggested that competence in performing basic orienteering techniques efficiently was a key variable differentiating between the elite and the nonelite athletes. The results are discussed in comparison with previous studies.