Identifying the task variables that predict object assembly difficulty.

We investigated the physical attributes of an object that influence the difficulty of its assembly. Identifying attributes that contribute to assembly difficulty will provide a method for predicting assembly complexity

AI Lab Faculty

This document is meant to introduce new graduate students in the MIT AI Lab to the faculty members of the laboratory and their research interests. Each entry consists of the faculty member's picture, if available, some information on how to reach them, their responses to a few survey questions, and a few paragraphs excerpted from the AI Lab President's Report, as edited by Patrick Winston.MIT Artificial Intelligence Laborator

The estimation of a preference-based measure of health from the SF-36

This paper reports on the findings of a study to derive a preference-based measure of health from the SF-36 for use in economic evaluation. The SF-36 was revised into a six-dimensional health state classification called the SF-6D. A sample of 249 states defined by the SF-6D have been valued by a representative sample of 611 members of the UK general population, using standard gamble. Models are estimated for predicting health state valuations for all 18,000 states defined by the SF-6D. The econometric modelling had to cope with the hierarchical nature of the data and its skewed distribution. The recommended models have produced significant coefficients for levels of the SF-6D, which are robust across model specification. However, there are concerns with some inconsistent estimates and over prediction of the value of the poorest health states. These problems must be weighed against the rich descriptive ability of the SF-6D, and the potential application of these models to existing and future SF-36 data set

Child‐level factors affecting rate of learning to write in first grade

[EN] Background.Written composition requires handwriting, spelling, and text planning skills,all largely learned through school instruction. Students’ rate of learning to compose textin their first months at school will depend, in part, on their literacy-related abilities atschool start. These effects have not previously been explored.Aim.We aimed to establish the effects of various literacy-related abilities on thelearning trajectory of first-grade students as they are taught to write.Sample.179 Spanish first-grade students (94 female, mean age 6.1 years) writing 3,512texts.Method.Students were assessed at start of school for spelling, transcription fluency,letter knowledge, phonological awareness, handwriting accuracy, word reading, and non-verbal reasoning. They were then taught under a curriculum that included researcher-designed instruction in handwriting, spelling, and ideation. Students’ compositionperformance was probed at very regular intervals over their first 13 weeks at school.Results.Controlling for age, overall performance was predicted by spelling, transcrip-tion fluency, handwriting accuracy, word reading, and non-verbal reasoning. Moststudents showed rapid initial improvement, but then much slower learning. Weak spellers(and to a lesser extent less fluent hand-writers) showed weaker initial performance, butthen steady improvement across the study period.SIMinisterio de Economía y Competitivida

Postmortomics:The potential of untargeted metabolomics to highlight markers for time since death

The success of forensic investigations involving fatalities very often depends on the establishment of the correct timeline of events. Currently used methods for estimating the postmortem interval (PMI) are mostly dependent on the professional and tacit experience of the investigator, and often with poor reliability in the absence of robust biological markers. The aim of this study was to investigate the potential of metabolomic approaches to highlight molecular markers for PMI. Rat and human muscle tissues, collected at various times postmortem, were analyzed using an untargeted metabolomics approach. Levels of certain metabolites (skatole, xanthine, n-acetylneuraminate, 1-methylnicotinamide, choline phosphate, and uracil) as well as most proteinogenic amino acids increased steadily postmortem. Threonine, tyrosine, and lysine show the most predictable evolution over the postmortem period, and may thus have potential for possible PMI markers in the future. This study demonstrates how a biomarker discovery approach can be extended to forensic investigations using untargeted metabolomics

The Relationship between Social Support Correlates and Feelings of Loneliness among Male UK Recreational Anglers

The benefits of access to blue spaces (exposure to aquatic environments) have been well reported. One common activity conducted in these spaces is recreational angling. Studies have shown that several correlates are associated with recreational angling, including lower incidence of anxiety disorders compared to non-anglers. What is currently unknown, is how measures of social support relate to feelings of loneliness in this population. The aim of this study, therefore, was to examine experiences of loneliness and social support in male UK anglers. In total, 1752 participants completed an online survey. Results showed a positive linear trend between the number of friends and family that anglers (a) heard from at least once a month; (b) trust enough to talk about private matters, and (c) could call upon for help and feelings of loneliness. Furthermore, more than half of the sample reported hardly ever or never having feelings of loneliness, suggesting that recreational angling does not affect feelings of loneliness

The online management of writing processes and their contribution to text quality in upper-primary students

p. 311-318La distribución temporal de los procesos de escritura y su contribucióna la calidad textual al final de Educación Primaria. Antecedentes: el manejo temporal de los procesos de escritura es un factor importante que influye en la composición de textos de calidad. En este estudio se analiza el tiempo que los estudiantes de 5º-6º de Primaria dedican a los procesos de escritura, su distribución temporal durante la composición y en qué medida ambos aspectos contribuyen a la calidad textual. Método: 120 estudiantes de 5º-6º de Primaria escribieron un texto argumentativo en parejas usando pensamiento en voz alta. Las verbalizaciones fueron analizadas en base a diferentes procesos y subprocesos de escritura. Resultados: los estudiantes hacen escaso uso de procesos de planificación y revisión textual. La planificación, relacionada principalmente con la generación de información, suele activarse al inicio del proceso de escritura. La revisión, que básicamente implica lectura, aparece al final del proceso escritor. El tiempo empleado por los escritores en los diferentes procesos o el momento en que son activados durante la composición no se relaciona con la calidad textual. Conclusiones: los estudiantes de 5º-6º de Primaria no solo hacen un escaso uso de procesos de planificación y revisión, sino que este es ineficaz. Por ello, es necesario instruir al alumnado en el uso de dichos procesos desde edades tempranas.S

Diferencias en la auto-eficacia lectora entre cursos en la escolaridad y en función del género

Se analizan las diferencias en la auto-eficacia lectora entre cursos a lo largo de la escolaridad and en función del sex en una muestra de 1.060 alumnos españoles distribuidos desde 3o EP a 4o ESO. Se utilizó una escala de auto-eficacia lectora que diferencia tres dimensiones de acuerdo con el nivel de complejidad de las habilidades de lectura implicadas en la tarea de comprensión lectora, diferenciando entre habilidades ligadas a la decodificación, la construcción del texto base y el modelo de situación. Los resultados sugieren un patrón de cambio diferenciado en la auto-eficacia lectora en función de las diferentes dimensiones evaluadas, mostrando un incremento en la auto-eficacia en decodificación y textual, y un decrecimiento en la relacionada con el modelo de situación. En todas las dimensiones de la auto-eficacia existe un periodo crítico en el paso a la Secundaria. No se obtuvieron diferencias en la auto- eficacia lectora en función del género a lo largo de la escolaridad.

Combined deployable keystroke logging and eyetracking for investigating L2 writing fluency

Although fluency is an important sub-construct of language proficiency, it has not received as much attention in L2 writing research as complexity and accuracy have, in part due to the lack of methodological approaches for the analysis of large datasets of writing-process data. This article presents a method of time-aligned keystroke logging and eye tracking and reports an empirical study investigating L2 writing fluency through this method. Twenty-four undergraduate students at a private university in Turkey performed two writing tasks delivered through a web text editor with embedded keystroke logging and eye-tracking capabilities. Linear mixed-effects models were fit to predict indices of pausing and reading behaviors based on language status (L1 vs. L2) and linguistic context factors. Findings revealed differences between pausing and eye-fixation behavior in L1 and L2 writing processes. The paper concludes by discussing the affordances of the proposed method from the theoretical and practical standpoints