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OBJECTIVE: 18F-Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) allows noninvasive assessment of glucose metabolism and radiodensity in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). We aimed to address the effects of ageing and metabolic factors on abdominal adipose tissue. DESIGN, PATIENTS AND MEASUREMENTS: We retrospectively analyzed data from 435 healthy men (mean 42.8 years) who underwent a health check-up programme twice, at baseline and the 5-year follow-up. The mean standardized uptake value (SUV) was measured using SAT and VAT and divided by the liver SUV. The mean Hounsfield units (HU) of the SAT and VAT were measured from the CT scans. The effects of clinical variable clusters on SUVR were investigated using Bayesian hierarchical modelling; metabolic cluster (BMI, waist-to-hip ratio, fat percentage, muscle percentage*-1, HOMA-IR), blood pressure (systolic, diastolic), glucose (fasting plasma glucose level, HbA1c) and C-reactive protein. RESULTS: All the clinical variables changed during the 5-year follow-up period. The SUVR and HU of the VAT increased during follow-up; however, those of the SAT did not change. SUVR and HU were positively correlated with both VAT and SAT. SAT and VAT SUVR were negatively associated with metabolic clusters. CONCLUSIONS: Ageing led to increased glucose metabolism and radiodensity in VAT, but not in SAT. VAT may reflect the ageing process more directly than SAT. Glucose metabolism was higher and radiodensity was lower in VAT than in SAT, probably owing to differences in gene expression and lipid density. Both glucose metabolism and radiodensity of VAT and SAT reflect metabolic status.
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When investigating unobservable, complex traits, data collection and aggregation processes can introduce distinctive features to the data such as boundedness, measurement error, clustering, outliers, and heteroscedasticity. Failure to collectively address these features can result in statistical challenges that prevent the investigation of hypotheses regarding these traits. This study aimed to demonstrate the efficacy of the Bayesian beta-proportion generalized linear latent and mixed model (beta-proportion GLLAMM) (Rabe-Hesketh et al., Psychometrika, 69(2), 167-90, 2004a, Journal of Econometrics, 128(2), 301-23, 2004c, 2004b; Skrondal and Rabe-Hesketh 2004) in handling data features when exploring research hypotheses concerning speech intelligibility. To achieve this objective, the study reexamined data from transcriptions of spontaneous speech samples initially collected by Boonen et al. (Journal of Child Language, 50(1), 78-103, 2023). The data were aggregated into entropy scores. The research compared the prediction accuracy of the beta-proportion GLLAMM with the normal linear mixed model (LMM) (Holmes et al., 2019) and investigated its capacity to estimate a latent intelligibility from entropy scores. The study also illustrated how hypotheses concerning the impact of speaker-related factors on intelligibility can be explored with the proposed model. The beta-proportion GLLAMM was not free of challenges; its implementation required formulating assumptions about the data-generating process and knowledge of probabilistic programming languages, both central to Bayesian methods. Nevertheless, results indicated the superiority of the model in predicting empirical phenomena over the normal LMM, and its ability to quantify a latent potential intelligibility. Additionally, the proposed model facilitated the exploration of hypotheses concerning speaker-related factors and intelligibility. Ultimately, this research has implications for researchers and data analysts interested in quantitatively measuring intricate, unobservable constructs while accurately predicting the empirical phenomena.
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Teorema de Bayes , Entropía , Inteligibilidad del Habla , Humanos , Inteligibilidad del Habla/fisiología , Modelos Lineales , Modelos Estadísticos , Interpretación Estadística de DatosRESUMEN
PURPOSE: Aberrant dopaminergic function is linked with motor, psychotic, and affective symptoms, but studies have typically compared a single patient group with healthy controls. METHODS: Here, we investigated the variation in striatal (caudate nucleus, nucleus accumbens, and putamen) and thalamic type 2 dopamine receptor (D2R) availability using [11C]raclopride positron emission tomography (PET) data from a large sample of 437 humans including healthy controls, and subjects with Parkinson's disease (PD), antipsychotic-naïve schizophrenia, severe violent behavior, pathological gambling, depression, and overweight. We analyzed regional group differences in D2R availability. We also analyzed the interregional correlation in D2R availability within each group. RESULTS: Subjects with PD showed the clearest decline in D2R availability. Overall, the groups showed high interregional correlation in D2R availability, while this pattern was weaker in violent offenders. Subjects with schizophrenia, pathological gambling, depression, or overweight did not show clear changes in either the regional receptor availability or the interregional correlation. CONCLUSION: We conclude that the dopaminergic changes in neuropsychiatric conditions might not only affect the overall receptor availability but also how coupled regions are across people. The region-specific receptor availability more profoundly links to the motor symptoms, while the between-region coupling might be disrupted in violence.
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Sobrepeso , Enfermedad de Parkinson , Humanos , Receptores de Dopamina D2/metabolismo , Tomografía Computarizada por Rayos X , Tomografía de Emisión de Positrones , Cuerpo Estriado , DopaminaRESUMEN
In this paper we explore the influences of normal ageing and verb transitivity on sentence production. The underlying aim is to provide a foundation for further research on sentence production in Alzheimer's disease (AD). We used a computer-based written sentence production task, designed to elicit intransitive, monotransitive and ditransitive sentences. Data was collected using keystroke logging, a technique to capture the entire typing process. Data of ninety healthy elderly was analysed focusing on the following writing process variables: time on task, production time and pause times. Results show that age influences time on task, pause time before sentences and within words. Verb transitivity influences time on task, production time and pause time between words. For pause time before sentences and between words, an interaction effect between age and verb transitivity was found as well. These results indicate that a follow-up study with AD patients should not attribute a slowdown in one of these variables to the disease in its entirety but should instead be compared with the slowdown in age-matched healthy peers.
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In effectiveness literature, voices are rising to embrace learning contents beyond mathematics, science, and language. Meanwhile, international policy documents such as the United Nations 2019 Climate Action Summit Report point at the importance of action for sustainable development for establishing acceptable life conditions for current and future generations. Therefore, a candidate learning outcome for broadening effectiveness research's scope is action competence in sustainable development (ACiSD), which consists of the relevant knowledge, willingness, capacity expectations, and outcome expectancy regarding actions for sustainable development. In order to initiate adding ACiSD as a learning outcome to effectiveness research, the current study contributed to establishing that formal education plays a part in changes in students' ACiSD. Firstly, we studied how much variance in ACiSD can be attributed to what happens in classrooms. Secondly, we looked into how class groups' and early adolescent students' ACiSD changed after one school year. Following recommendations for rigour in effectiveness research, we performed multilevel analyses on survey data (question one: n = 1398; question two: n = 633). Our evidence showed that 11% of variance in ACiSD was attributable to what happens in classrooms with explained variance in the subconstructs ranging between 7.2 and 14.2%. Furthermore, individual students as well as class groups showed higher ACiSD scores when comparing measurements at beginning and end of one school year. We conclude that the classroom level matters to changes in ACiSD within early adolescents. Further research can now look into how and to which extent teachers' educational approaches affect these changes.
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In this article, we explore if the observation of writing behavior can assist in the screening and follow-up of mild cognitive impairment (MCI) and mild dementia due to Alzheimer's disease (AD). To this end, we examined the extent to which overall writing process measures and pausing behavior during writing differed between 15 cognitively impaired patients and 15 age- and gender-matched healthy controls. Participants completed two typed picture description tasks that were registered with Inputlog, a keystroke logging program that captures keyboard activity during text production. The following variables were analyzed with mixed-effects models: time on task; number of characters, pauses and Pause-bursts per minute; proportion of pause time; duration of Pause-bursts; and pause time between words. For pause time between words, also the effect of pauses preceding specific word categories was analyzed. Results showed a main effect of group on all variables. In addition, for pause time between words a main effect of part-of-speech was found as well. Results indicate that writing process analysis can possibly serve as a supplementary tool for the screening and follow-up of AD.
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Auditory brainstem implantation (ABI) is a relative recent development in paediatric hearing restoration. Consequently, young-implanted children's productive language has not received much attention. This study investigated speech intelligibility of children with ABI (N = 3) in comparison to children with cochlear implants (CI) and children with typical hearing (TH). Spontaneous speech samples were recorded from children representing the three groups matched on cumulative vocabulary level. Untrained listeners (N = 101) rated the intelligibility of one-word utterances on a continuous scale and transcribed each utterance. The rating task yielded a numerical score between 0 and 100, and similarities and differences between the listeners' transcriptions were captured by a relative entropy score. The speech intelligibility of children with CI and children with TH was similar. Speech intelligibility of children with ABI was well below that of the children with CI and TH. But whereas one child with ABI's intelligibility approached that of the control groups with increasing lexicon size, the intelligibility of the two other children with ABI did not develop in a similar direction. Overall, speech intelligibility was only moderate in the three groups of children, with quite low ratings and considerable differences in the listeners' transcriptions, resulting in high relative entropy scores.
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Implantes Auditivos de Tronco Encefálico , Implantación Coclear , Implantes Cocleares , Percepción del Habla , Niño , Humanos , Inteligibilidad del Habla , Implantación Coclear/métodosRESUMEN
This mixed-method quasi-experimental study examined whether metaconceptual grammar teaching impacts on (a) students' L1 grammatical understanding, (b) their 'blind' use of grammatical concepts and (c) their preference of using explicit grammatical concepts over everyday concepts in explaining grammatical problems. Previous research, involving single group pre-postintervention designs, found positive effects for metaconceptual interventions on secondary school students' grammatical reasoning ability, although a negative side effect seemed to be that some students started using grammatical concepts 'blindly' (i.e., in an inaccurate way). While there are thus important clues that metaconceptual grammar teaching may lead to increased grammatical understanding, there is a great need for more robust empirical research. The current study, involving 196 Dutch 14-year old pre-university students, is a methodological improvement of previous work, adopting a switching replications design. Bayesian multivariate analyses indicate medium to large effects from the metaconceptual intervention on students' grammatical understanding. The study found a similar effect of the intervention on students' ability to use explicit grammatical concepts over everyday concepts in tackling grammatical problems. No evidence for increased 'blind' concept use as a negative byproduct of the intervention was found. Additional qualitative analyses of in-intervention tasks provided further evidence for the effectiveness of metaconceptual interventions, and seemed to indicate that cases of blind concept use, rather than being a negative side effect, might actually be part of a gradual process of students' growing understanding of grammatical (meta)concepts. We discuss these findings in relation to previous work and conclude that linguistic metaconcepts can improve L1 grammatical understanding.
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Escolaridad , Lenguaje , Lingüística/métodos , Estudiantes/estadística & datos numéricos , Enseñanza/normas , Adolescente , Teorema de Bayes , Femenino , Humanos , Masculino , Países Bajos , Ensayos Clínicos Controlados no Aleatorios como AsuntoRESUMEN
Researchers often decide on the number of trials included in an experiment without adhering to an empirical method or framework. This might compromise generalizability and unnecessarily increase participant burden. In this article we want to put forward generalizability theory as a guide for task reduction. We will use a sentence production task to demonstrate how a generalizability and a decision study can help researchers to estimate the minimum number of trials and of items per trial that are necessary to generalize over trials. We obtained writing process data for 116 participants. Each of them completed a sentence production task that had 40 trials. Pause times between and within all words, target nouns and target verbs were logged with the keystroke logging tool ScriptLog. Results demonstrate that generalizability theory can serve as an empirical framework to ensure generalizable measurements on the one hand, and reduce participant burden to a minimum on the other. This finding is particularly valuable for studies with vulnerable target groups, such as participants suffering from aphasia, dyslexia or Alzheimer's disease.
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Afasia , Lenguaje , Adulto , Humanos , EscrituraRESUMEN
CONSTRUCT: The authors aimed to investigate the utility of the comparative judgment method for assessing students' written self-reflections. BACKGROUND: Medical practitioners' reflective skills are increasingly considered important and therefore included in the medical education curriculum. However, assessing students' reflective skills using rubrics does not appear to guarantee adequate inter-rater reliabilities. Recently, comparative judgment was introduced as a new method to evaluate performance assessments. This study investigates the merits and limitations of the comparative judgment method for assessing students' written self-reflections. More specifically, it examines the reliability in relation to the time spent assessing, the correlation between the scores obtained using the two methods (rubrics and comparative judgment), and, raters' perceptions of the comparative judgment method. APPROACH: Twenty-two self-reflections, that had previously been scored using a rubric, were assessed by a group of eight raters using comparative judgment. Two hundred comparisons were completed and a rank order was calculated. Raters' impressions were investigated using a focus group. FINDINGS: Using comparative judgment, each self-reflection needed to be compared seven times with another self-reflection to reach a scale separation reliability of .55. The inter-rater reliability of rating (ICC, (1, k)) using rubrics was .56. The time investment required for these reliability levels in both methods was around 24 minutes. The Kendall's tau rank correlation indicated a strong correlation between the scores obtained via both methods. Raters reported that making comparisons made them evaluate the quality of self-reflections in a more nuanced way. Time investment was, however, considered heavy, especially for the first comparisons. Although raters appreciated that they did not have to assign a grade to each self-reflection, the fact that the method does not automatically lead to a grade or feedback was considered a downside. CONCLUSIONS: First evidence was provided for the comparative judgment method as an alternative to using rubrics for assessing students' written self-reflections. Before comparative judgment can be implemented for summative assessment, more research is needed on the time investment required to ensure no contradictory feedback is given back to students. Moreover, as the comparative judgment method requires an additional standard setting exercise to obtain grades, more research is warranted on the merits and limitations of this method when a pass/fail approach is used.
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Juicio , Estudiantes de Medicina , Evaluación Educacional , Humanos , Reproducibilidad de los Resultados , Autoevaluación (Psicología) , EscrituraRESUMEN
BACKGROUND: Up until now, empirical studies in the Student Approaches to Learning field have mainly been focused on the use of self-report instruments, such as interviews and questionnaires, to uncover differences in students' general preferences towards learning strategies, but have focused less on the use of task-specific and online measures. AIMS: This study aimed at extending current research on students' learning strategies by combining general and task-specific measurements of students' learning strategies using both offline and online measures. We want to clarify how students process learning contents and to what extent this is related to their self-report of learning strategies. SAMPLE: Twenty students with different generic learning profiles (according to self-report questionnaires) read an expository text, while their eye movements were registered to answer questions on the content afterwards. METHODS: Eye-tracking data were analysed with generalized linear mixed-effects models. RESULTS: The results indicate that students with an all-high profile, combining both deep and surface learning strategies, spend more time on rereading the text than students with an all-low profile, scoring low on both learning strategies. CONCLUSIONS: This study showed that we can use eye-tracking to distinguish very strategic students, characterized using cognitive processing and regulation strategies, from low strategic students, characterized by a lack of cognitive and regulation strategies. These students processed the expository text according to how they self-reported.
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Medidas del Movimiento Ocular , Aprendizaje/fisiología , Lectura , Autoinforme , Estudiantes , Adolescente , Adulto , Femenino , Humanos , Masculino , Adulto JovenRESUMEN
Comparative judgment (CJ) is an alternative method for assessing competences based on Thurstone's law of comparative judgment. Assessors are asked to compare pairs of students work (representations) and judge which one is better on a certain competence. These judgments are analyzed using the Bradly-Terry-Luce model resulting in logit estimates for the representations. In this context, the Scale Separation Reliability (SSR), coming from Rasch modeling, is typically used as reliability measure. But, to the knowledge of the authors, it has never been systematically investigated if the meaning of the SSR can be transferred from Rasch to CJ. As the meaning of the reliability is an important question for both assessment theory and practice, the current study looks into this. A meta-analysis is performed on 26 CJ assessments. For every assessment, split-halves are performed based on assessor. The rank orders of the whole assessment and the halves are correlated and compared with SSR values using Bland-Altman plots. The correlation between the halves of an assessment was compared with the SSR of the whole assessment showing that the SSR is a good measure for split-half reliability. Comparing the SSR of one of the halves with the correlation between the two respective halves showed that the SSR can also be interpreted as an interrater correlation. Regarding SSR as expressing a correlation with the truth, the results are mixed.
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Longitudinal data is almost always burdened with missing data. However, in educational and psychological research, there is a large discrepancy between methodological suggestions and research practice. The former suggests applying sensitivity analysis in order to the robustness of the results in terms of varying assumptions regarding the mechanism generating the missing data. However, in research practice, participants with missing data are usually discarded by relying on listwise deletion. To help bridge the gap between methodological recommendations and applied research in the educational and psychological domain, this study provides a tutorial example of sensitivity analysis for latent growth analysis. The example data concern students' changes in learning strategies during higher education. One cohort of students in a Belgian university college was asked to complete the Inventory of Learning Styles-Short Version, in three measurement waves. A substantial number of students did not participate on each occasion. Change over time in student learning strategies was assessed using eight missing data techniques, which assume different mechanisms for missingness. The results indicated that, for some learning strategy subscales, growth estimates differed between the models. Guidelines in terms of reporting the results from sensitivity analysis are synthesised and applied to the results from the tutorial example.
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Evaluación Educacional/métodos , Aprendizaje/fisiología , Estudiantes/psicología , Bélgica , Evaluación Educacional/estadística & datos numéricos , Humanos , Estudios Longitudinales , Reproducibilidad de los Resultados , Proyectos de Investigación/normas , Proyectos de Investigación/estadística & datos numéricos , Sensibilidad y Especificidad , Estudiantes/estadística & datos numéricos , Encuestas y Cuestionarios , Factores de Tiempo , UniversidadesRESUMEN
This study investigated the acoustic characteristics of the Belgian Standard Dutch vowels in children with hearing impairment and in children with normal hearing. In a balanced experimental design, the 12 vowels of Belgian Standard Dutch were recorded in three groups of children: a group of children with normal hearing, a group with a conventional hearing aid and a group with a cochlear implant. The formants, the surface area of the vowel space and the acoustic differentiation between the vowels were determined. The analyses revealed that many of the vowels in hearing-impaired children showed a reduction of the formant values. This reduction was particularly significant with respect to F2. The size of the vowel space was significantly smaller in the hearing-impaired children. Finally, a smaller acoustic differentiation between the vowels was observed in children with hearing impairment. The results show that even after 5 years of device use, the acoustic characteristics of the vowels in hearing-assisted children remain significantly different as compared to their NH peers.
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Implantes Cocleares , Corrección de Deficiencia Auditiva , Audífonos , Fonética , Percepción del Habla , Medición de la Producción del Habla , Niño , Preescolar , Femenino , Humanos , Masculino , Valores de Referencia , Espectrografía del Sonido , Acústica del Lenguaje , Pruebas de Articulación del Habla , Inteligibilidad del HablaRESUMEN
OBJECTIVES: This study targets to analyse mother-child interactions in two groups of children with different hearing levels: normally hearing children (NH) and congenitally hearing-impaired children with a cochlear implant (CI). Mothers of hearing-impaired children are shown to use less speech in interactions with their children than mothers of normally hearing children. We aim to investigate whether this observation also holds for mothers of CI children. METHODS: Transcriptions of spontaneous conversations of ten CI children and ten NH children were analysed. We examined whether mothers responded to their children's utterances and whether they repeated or incorporated them in their own follow-up. Conversations were analysed in two consecutive stages, namely a prelexical stage and a lexical one. RESULTS: Mothers of CI children responded significantly more often to their children's utterances in both the prelexical and lexical stage. They also incorporated their children's utterances more often, however this was only significant in the lexical stage. The type of child utterance was an important trigger for the amount of mothers' responses. All mothers responded significantly more often to lexical utterances in the lexical stage. In the prelexical stage, however, precanonical utterances received the same amount of responses as canonical babbles. Nevertheless, all mothers incorporated canonical babbles more often than precanonical vocalisations in the prelexical stage and lexical utterances more often in the lexical stage. CONCLUSIONS: First, mothers of CI children are more responsive to their children's utterances suggesting that they are aware of their children's hearing status. Second, type of child utterance is an important trigger for both mothers' response level and mothers' type of response in the prelexical and lexical stage.
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Implantes Cocleares , Pérdida Auditiva/psicología , Relaciones Madre-Hijo/psicología , Madres/psicología , Comunicación no Verbal/psicología , Habla , Adulto , Estudios de Casos y Controles , Lenguaje Infantil , Preescolar , Implantación Coclear , Femenino , Pérdida Auditiva/congénito , Pérdida Auditiva/terapia , Humanos , Lactante , MasculinoRESUMEN
The change in learning strategies during higher education is an important topic of research in the Student Approaches to Learning field. Although the studies on this topic are increasingly longitudinal, analyses have continued to rely primarily on traditional statistical methods. The present research is innovative in the way it uses a multi-indicator latent growth analysis in order to more accurately estimate the general and differential development in learning strategy scales. Moreover, the predictive strength of the latent growth models are estimated. The sample consists of one cohort of Flemish University College students, 245 of whom participated in the three measurement waves by filling out the processing and regulation strategies scales of the Inventory of Learning Styles--Short Versions. Independent-samples t-tests revealed that the longitudinal group is a non-random subset of students starting University College. For each scale, a multi-indicator latent growth model is estimated using Mplus 6.1. Results suggest that, on average, during higher education, students persisting in their studies in a non-delayed manner seem to shift towards high-quality learning and away from undirected and surface-oriented learning. Moreover, students from the longitudinal group are found to vary in their initial levels, while, unexpectedly, not in their change over time. Although the growth models fit the data well, significant residual variances in the latent factors remain.
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Educación , Aprendizaje , Modelos Teóricos , Análisis de Varianza , Educación/tendencias , Humanos , Estudiantes , Encuestas y Cuestionarios , UniversidadesRESUMEN
BACKGROUND: Although the evidence in support of the variability of students' learning strategies has expanded in recent years, less is known about the explanatory base of these individual differences in terms of the joint influences of personal and contextual characteristics. AIMS: Previous studies have often investigated how student learning is associated with either personal or contextual factors. This study takes an integrative research perspective into account and examines the joint effects of personality, academic motivation, and teaching strategies on students' learning strategies in a same educational context in first-year higher education. SAMPLE: In this study, 1,126 undergraduate students and 90 lecturers from eight professional bachelor programmes in a university college participated. METHODS: Self-report measures were used to measure students' personality, academic motivation, and learning strategies. Students' processing and regulation strategies are mapped using the Inventory of Learning Styles. Key characteristics of more content-focused versus learning-focused teaching strategies were measured. Multivariate multi-level analysis was used to take the nested data structure and interrelatedness of learning strategies into account. RESULTS: Different personality traits (openness, conscientiousness, and neuroticism) and academic motivation (amotivation, autonomous, and controlled motivation) were found to be independently associated with student learning strategies. Besides these student characteristics, also teaching strategies were found to be directly associated with learning strategies. CONCLUSIONS: The study makes clear that the impact of teaching strategies on learning strategies in first-year higher education cannot be overlooked nor overinterpreted, due to the importance of students' personality and academic motivation which also partly explain why students learn the way they do.
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Individualidad , Aprendizaje , Motivación , Estudiantes/psicología , Enseñanza/métodos , Docentes , Femenino , Humanos , Masculino , Personalidad , Inventario de Personalidad , Encuestas y Cuestionarios , UniversidadesRESUMEN
The Revised Two-Factor Study Process Questionnaire (R-SPQ-2F) is used to examine students' study approaches in higher education. The questionnaire assumes to measure two factors: a deep and a surface study approach. Analyses into the validity and reliability of the original English R-SPQ-2F yielded positive results. In this study, we examined the degree to which these positive results can also be found for the Dutch version that we developed. By comparing our results with the results of earlier studies in different cultures, we conclude cross-cultural sensitivity is an important point to be borne in mind when using the R-SPQ-2F. Our research supports the validity and reliability of our Dutch version of the R-SPQ-2F.
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Encuestas y Cuestionarios , Humanos , Aprendizaje , EstudiantesRESUMEN
OBJECTIVE: Studies investigating language skills of children after cochlear implantation usually use global language proficiency scores and rarely tackle the acquisition of specific language phenomena (word classes, grammatical constructions, etc.). Furthermore, research is largely restricted to frequent word classes (nouns, verbs). The present study targets the acquisition of adjectives (e.g. big, intelligent) by children implanted before their second birthday. Adjectives constitute a relatively infrequent, but functionally important word class and were shown to be good indicators of language delays and impairments. METHOD: Nine cochlear-implanted (CI) children and 60 age-matched normally hearing (NH) controls participated in the study. The CI children were followed longitudinally from ages 2 to 7; control data were collected in a cross-sectional manner (10 children per age group). Samples of children's spontaneous interactions with their caregivers were transcribed and analyzed for adjective use (frequency, lexical diversity, complexity of syntactic constructions, and morphological correctness). RESULTS: The performance of the CI subjects was not significantly different from that of NH peers on adjective frequency and lexical diversity. On these measures, both groups reached adult levels by age 3. However, the CI group had a significant delay in the acquisition of complex syntactic constructions. The NH subjects produced adjectives in adult-like grammatical constructions from age 3 onwards, whereas their CI peers lagged behind until age 5. The speech of the CI participants also featured morphological errors that are not characteristic of typical development (inflection of predicative adjectives). However, the overall error rate was low. CONCLUSIONS: The findings suggest that CI children have particular difficulty with grammatical items (bound morphemes, copulas) that are less salient in the flow of speech than content words. Nevertheless, children implanted before their second birthday are able to catch up with their hearing peers by age 5, even in the use of relatively infrequent word classes.