2,348 research outputs found

    Issues arising from the HASTE experiments

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    [FIRST PARAGRAPH] The HASTE project work discussed in the foregoing papers can be depicted as being aimed at answering two questions: “Does greater secondary task load from an In-Vehicle Information System (IVIS) lead to an identifiably worse performance in the primary task of driving?” and “How much distraction is too much?”. There is, of course, a huge amount of literature examining the effect of distraction on driving. Some of this concerns visual distraction (e.g. Holohan, Culler & Wilcox, 1978; Dingus, Antin, Hulse & Wierwille, 1989; Wierwille & Tijerina, 1996; Wallace, 2003), while other parts cover distraction from cognitive (auditory) tasks such as mobile phone use (e.g. Stevens & Paulo, 1999; Svenson & Patten, 2003). But, in spite of this large background of research, it can be argued that the HASTE work was pioneering in the sense that it attempted to differentiate between the effects of visual and cognitive distraction and at the same time it attempted to carefully control the “dose” of distraction administered at any one time. These dose-response studies were carried out in three common but quite different experimental settings, a laboratory set-up, advanced driving simulators, and in instrumented vehicles in the field. The project also examined the reliability of the evaluation, with for example six replications of the rural road studies across a variety of driving simulators in five different countries

    Unbounded Human Learning: Optimal Scheduling for Spaced Repetition

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    In the study of human learning, there is broad evidence that our ability to retain information improves with repeated exposure and decays with delay since last exposure. This plays a crucial role in the design of educational software, leading to a trade-off between teaching new material and reviewing what has already been taught. A common way to balance this trade-off is spaced repetition, which uses periodic review of content to improve long-term retention. Though spaced repetition is widely used in practice, e.g., in electronic flashcard software, there is little formal understanding of the design of these systems. Our paper addresses this gap in three ways. First, we mine log data from spaced repetition software to establish the functional dependence of retention on reinforcement and delay. Second, we use this memory model to develop a stochastic model for spaced repetition systems. We propose a queueing network model of the Leitner system for reviewing flashcards, along with a heuristic approximation that admits a tractable optimization problem for review scheduling. Finally, we empirically evaluate our queueing model through a Mechanical Turk experiment, verifying a key qualitative prediction of our model: the existence of a sharp phase transition in learning outcomes upon increasing the rate of new item introductions.Comment: Accepted to the ACM SIGKDD Conference on Knowledge Discovery and Data Mining 201

    RNA-seq reveals post-transcriptional regulation of Drosophila insulin-like peptide dilp8 and the neuropeptide-like precursor Nplp2 by the exoribonuclease Pacman/XRN1

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    Ribonucleases are critically important in many cellular and developmental processes and defects in their expression are associated with human disease. Pacman/XRN1 is a highly conserved cytoplasmic exoribonuclease which degrades RNAs in a 5' - 3' direction. In Drosophila, null mutations in pacman result in small imaginal discs, a delay in onset of pupariation and lethality during the early pupal stage. In this paper, we have used RNA-seq in a genome-wide search for mRNAs misregulated in pacman null wing imaginal discs. Only 4.2% of genes are misregulated ±>2-fold in pacman null mutants compared to controls, in line with previous work showing that Pacman has specificity for particular mRNAs. Further analysis of the most upregulated mRNAs showed that Pacman post-transcriptionally regulates the expression of the secreted insulin-like peptide Dilp8. Dilp8 is related to human IGF-1, and has been shown to co-ordinate tissue growth with developmental timing in Drosophila. The increased expression of Dilp8 is consistent with the developmental delay seen in pacman null mutants. Our analysis, together with our previous results, show that the normal role of this exoribonuclease in imaginal discs is to suppress the expression of transcripts that are crucial in apoptosis and growth control during normal development

    Pronunciation acquisition patterns of learners with different starting levels

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    This study described the results of an investigation into the effect of an intensive 12-week pronunciation course in British English which 30 Dutch female 1st-year university students of English took. They read out the same text before and after the course. Each student’s ‘before’ and ‘after’ tests were recorded. Before analysis of their results, students were split up into three groups on the basis of their general starting level: high, intermediate and low. The analysis involved a before- and after comparison of the pronunciation of eleven different phonemes: /æ, ɒ, ɔː, ʌ, ʊ, d, θ/, medial /t/, coda /r/, and syllable-final /d, v/. The analysis was done by means of both auditory and acoustic analysis. Four degrees of success (or lack thereof) were defined. The results show that the consonants required the least effort, as they were already relatively acceptable before the course started. This was true of students in general, regardless of initial starting level. The three levels of students are most distinguishable on the basis of the development of the consonants during the course. The weaker students’ consonants in particular benefitted from the course. The research revealed that initial level can be used to predict the trajectory of improvement. A general conclusion is that teachers may recognise types of students before the course starts and subject them to different types of teaching

    Is attending a mental process?

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    The nature of attention has been the topic of a lively research programme in psychology for over a century. But there is widespread agreement that none of the theories on offer manage to fully capture the nature of attention. Recently, philosophers have become interested in the debate again after a prolonged period of neglect. This paper contributes to the project of explaining the nature of attention. It starts off by critically examining Christopher Mole’s prominent “adverbial” account of attention, which traces the failure of extant psychological theories to their assumption that attending is a kind of process. It then defends an alternative, process-based view of the metaphysics of attention, on which attention is understood as an activity and not, as psychologists seem to implicitly assume, an accomplishment. The entrenched distinction between accomplishments and activities is shown to shed new light on the metaphysics of attention. It also provides a novel diagnosis of the empirical state of play
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