521 research outputs found
Understanding Test Takers' Choices in a Self-Adapted Test: A Hidden Markov Modeling of Process Data
With the rise of more interactive assessments, such as simulation- and game-based assessment, process data are available to learn about students' cognitive processes as well as motivational aspects. Since process data can be complicated due to interdependencies in time, our traditional psychometric models may not necessarily fit, and we need to look for additional ways to analyze such data. In this study, we draw process data from a study on self-adapted test under different goal conditions (Arieli-Attali, 2016) and use hidden Markov models to learn about test takers' choice making behavior. Self-adapted test is designed to allow test takers to choose the level of difficulty of the items they receive. The data includes test results from two conditions of goal orientation (performance goal and learning goal), as well as confidence ratings on each question. We show that using HMM we can learn about transition probabilities from one state to another as dependent on the goal orientation, the accumulated score and accumulated confidence, and the interactions therein. The implications of such insights are discussed
Calculating the random guess scores of multiple-response and matching test items
For achievement tests, the guess score is often used as a baseline for the lowest possible grade for score to grade transformations and setting the cut scores. For test item types such as multiple-response, matching and drag-and-drop, determin-ing the guess score requires more elaborate calculations than the more straight-forward calculation of the guess score for True-False and multiple-choice test item formats. For various variants of multiple-response and matching types with respect to dichotomous and polytomous scoring, methods for determining the guess score are presented and illustrated with practical applications. The implica-tions for theory and practice are discussed
Sound archaeology: terminology, Palaeolithic cave art and the soundscape
This article is focused on the ways that terminology describing the study of music and sound within archaeology has changed over time, and how this reflects developing methodologies, exploring the expectations and issues raised by the use of differing kinds of language to define and describe such work. It begins with a discussion of music archaeology, addressing the problems of using the term âmusicâ in an archaeological context. It continues with an examination of archaeoacoustics and acoustics, and an emphasis on sound rather than music. This leads on to a study of sound archaeology and soundscapes, pointing out that it is important to consider the complete acoustic ecology of an archaeological site, in order to identify its affordances, those possibilities offered by invariant acoustic properties. Using a case study from northern Spain, the paper suggests that all of these methodological approaches have merit, and that a project benefits from their integration
Investigating the Factor Structure of iSkillsâą
This article was added to the Knowledge Bank in December, 2023.This paper investigates the issue of internal validity in the context of complex assessments and constructs, focusing on Information and Communication Technology (ICT) literacy as measured by the iSkills assessment. Utilizing exploratory and confirmatory factor analyses, the paper aims to explore the internal structure of the iSkills assessment vis-Ă -vis unidimensional and multidimensional views of ICT literacy. The results indicate
that ICT literacy, as measured by iSkills, emerges more as an integrated skill set rather than as distinct domains. The paper contributes to the broader conversation on the internal structure of assessments designed for complex constructs
Maintaining and monitoring quality of a continuously administered digital assessment
Digital-first assessments are a new generation of high-stakes assessments that can be taken anytime and anywhere in the world. The flexibility, complexity, and high-stakes nature of these assessments pose quality assurance challenges and require continuous data monitoring and the ability to promptly identify, interpret, and correct anomalous results. In this manuscript, we illustrate the development of a quality assurance system for anomaly detection for a new high-stakes digital-first assessment, for which the population of test takers is still in flux. Various control charts and models are applied to detect and flag any abnormal changes in the assessment statistics, which are then reviewed by experts. The procedure of determining the causes of a score anomaly is demonstrated with a real-world example. Several categories of statistics, including scores, test taker profiles, repeaters, item analysis and item exposure, are monitored to provide context and evidence for evaluating the score anomaly as well as assure the quality of the assessment. The monitoring results and alerts are programmed to be automatically updated and delivered via an interactive dashboard every day
Exploring effects of Souvenaid on cerebral glucose metabolism in Alzheimer's disease
Introduction
Alzheimer's disease (AD) is associated with synapse loss. Souvenaid, containing the specific nutrient combination Fortasyn Connect, was designed to improve synapse formation and function. The NL-ENIGMA study explored the effect of Souvenaid on synapse function in early AD by assessing cerebral glucose metabolism (CMRglc) with 18F-fluorodeoxyglucose ([18F]FDG) positron emission tomography (PET).
Methods
We conducted an exploratory double-blind randomized controlled single-center trial. Fifty patients with mild cognitive impairment or mild dementia with evidence of amyloid pathology (cerebrospinal fluid or PET) were stratified for MMSE (20â24 and 25â30) and randomly 1:1 allocated to 24-week daily administration of 125 mL Souvenaid (n = 25) or placebo (n = 25). Dynamic 60-minute [18F]FDG-PET scans (21 frames) with arterial sampling were acquired at baseline and 24 weeks. CMRglc was estimated by quantitative (Ki) and semiquantitative (standardized uptake value ratio, reference cerebellar gray matter) measurements in five predefined regions of interest and a composite region of interest. Change from baseline in CMRglc was compared between treatment groups by analysis of variance, adjusted for baseline CMRglc and MMSE stratum. Additional exploratory outcome parameters included voxel-based analyses by Statistical Parametric Mapping.
Results
No baseline differences between treatment groups were found (placebo/intervention: n = 25/25; age 66 ± 8/65 ± 7 years; female 44%/48%; MMSE 25 ± 3/25 ± 3). [18F]FDG-PET data were available for quantitative (placebo n = 19, intervention n = 18) and semiquantitative (placebo n = 20, intervention n = 22) analyses. At follow-up, no change within treatment groups and no statistically significant difference in change between treatment groups in CMRglc in any regions of interest were found by both quantitative and semiquantitative analyses. No treatment effect was found in the cerebellar gray matter using quantitative measures. The additional Statistical Parametric Mapping analyses did not yield consistent differences between treatment groups.
Discussion
In this exploratory trial, we found no robust effect of 24-week intervention with Souvenaid on synapse function measured by [18F]FDG-PET. Possible explanations include short duration of treatment
Sequential Effects in Judgements of Attractiveness: The Influences of Face Race and Sex
In perceptual decision-making, a personâs response on a given trial is influenced by their response on the immediately preceding trial. This sequential effect was initially demonstrated in psychophysical tasks, but has now been found in more complex, real-world judgements. The similarity of the current and previous stimuli determines the nature of the effect, with more similar items producing assimilation in judgements, while less similarity can cause a contrast effect. Previous research found assimilation in ratings of facial attractiveness, and here, we investigated whether this effect is influenced by the social categories of the faces presented. Over three experiments, participants rated the attractiveness of own- (White) and other-race (Chinese) faces of both sexes that appeared successively. Through blocking trials by race (Experiment 1), sex (Experiment 2), or both dimensions (Experiment 3), we could examine how sequential judgements were altered by the salience of different social categories in face sequences. For sequences that varied in sex alone, own-race faces showed significantly less opposite-sex assimilation (male and female faces perceived as dissimilar), while other-race faces showed equal assimilation for opposite- and same-sex sequences (male and female faces were not differentiated). For sequences that varied in race alone, categorisation by race resulted in no opposite-race assimilation for either sex of face (White and Chinese faces perceived as dissimilar). For sequences that varied in both race and sex, same-category assimilation was significantly greater than opposite-category. Our results suggest that the race of a face represents a superordinate category relative to sex. These findings demonstrate the importance of social categories when considering sequential judgements of faces, and also highlight a novel approach for investigating how multiple social dimensions interact during decision-making
Stretching and Bending the Frame â Green Possibilities in Popular Romantic Narratives
This article examines frame theory, popular culture, and environmental values. Reviewing frame theory across journalism, communication studies, linguistics, and fine art, it will examine in particular âcultural framingâ. Radical thought is invariably associated with the avant-garde, yet narrative or genre innovations in popular culture can also trigger âdeeperâ cognitive shifts, potentially transforming âcommon cultureâ. Citing comics, films, and animation, the main example is popular music and how Björk and British Sea Power have subverted generic and acoustic conventions (e.g. melody), and musicâs habitual romantic narratives, to re-frame humanânonhuman relationships ecologically. By stretching and manipulating frames, popular culture can adapt and engender environmental narratives for mass consumption
Three-layer model with absorption for conservative estimation of the maximum acoustic transmission coefficient through the human skull for transcranial ultrasound stimulation.
Transcranial ultrasound stimulation (TUS) has been shown to be a safe and effective technique for non-invasive superficial and deep brain stimulation. Safe and efficient translation to humans requires estimating the acoustic attenuation of the human skull. Nevertheless, there are no international guidelines for estimating the impact of the skull bone. A tissue independent, arbitrary derating was developed by the U.S. Food and Drug Administration to take into account tissue absorption (0.3 dB/cm-MHz) for diagnostic ultrasound. However, for the case of transcranial ultrasound imaging, the FDA model does not take into account the insertion loss induced by the skull bone, nor the absorption by brain tissue. Therefore, the estimated absorption is overly conservative which could potentially limit TUS applications if the same guidelines were to be adopted. Here we propose a three-layer model including bone absorption to calculate the maximum pressure transmission through the human skull for frequencies ranging between 100Â kHz and 1.5Â MHz. The calculated pressure transmission decreases with the frequency and the thickness of the bone, with peaks for each thickness corresponding to a multiple of half the wavelength. The 95th percentile maximum transmission was calculated over the accessible surface of 20 human skulls for 12 typical diameters of the ultrasound beam on the skull surface, and varies between 40% and 78%. To facilitate the safe adjustment of the acoustic pressure for short ultrasound pulses, such as transcranial imaging or transcranial ultrasound stimulation, a table summarizes the maximum pressure transmission for each ultrasound beam diameter and each frequency
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