124 research outputs found

    The Danger of Testing by Selecting Controlled Subsets, with Applications to Spoken-Word Recognition

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    When examining the effects of a continuous variable 'x' on an outcome 'y', a researcher might choose to dichotomize on 'x', dividing the population into two sets—low 'x' and high 'x'—and testing whether these two subpopulations differ with respect to 'y'. Dichotomization has long been known to incur a cost in statistical power, but there remain circumstances in which it is appealing: an experimenter might use it to control for confounding covariates through subset selection, by carefully choosing a subpopulation of Low and a corresponding subpopulation of High that are balanced with respect to a list of control variables, and then comparing the subpopulations’ 'y' values. This “divide, select, and test” approach is used in many papers throughout the psycholinguistics literature, and elsewhere. Here we show that, despite the apparent innocuousness, these methodological choices can lead to erroneous results, in two ways. First, if the balanced subsets of Low and High are selected in certain ways, it is possible to conclude a relationship between 'x' and 'y' not present in the full population. Specifically, we show that previously published conclusions drawn from this methodology—about the effect of a particular lexical property on spoken-word recognition—do not in fact appear to hold. Second, if the balanced subsets of Low and High are selected randomly, this methodology frequently fails to show a relationship between 'x' and 'y' that is present in the full population. Our work uncovers a new facet of an ongoing research effort: to identify and reveal the implicit freedoms of experimental design that can lead to false conclusions

    Putting the self in self-correction: findings from the loss-of-confidence project

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    Science is often perceived to be a self-correcting enterprise. In principle, the assessment of scientific claims is supposed to proceed in a cumulative fashion, with the reigning theories of the day progressively approximating truth more accurately over time. In practice, however, cumulative self-correction tends to proceed less efficiently than one might naively suppose. Far from evaluating new evidence dispassionately and infallibly, individual scientists often cling stubbornly to prior findings. Here we explore the dynamics of scientific self-correction at an individual rather than collective level. In 13 written statements, researchers from diverse branches of psychology share why and how they have lost confidence in one of their own published findings. We qualitatively characterize these disclosures and explore their implications. A cross-disciplinary survey suggests that such loss-of-confidence sentiments are surprisingly common among members of the broader scientific population yet rarely become part of the public record. We argue that removing barriers to self-correction at the individual level is imperative if the scientific community as a whole is to achieve the ideal of efficient self-correction

    D7.3 Report on simulator test results and driver acceptance of PROSPECT functions

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    The process of developing new automotive systems includes various testing cycles to assure a save operation in traffic. Physical system testing on test tracks is very important for this purpose, but rather expensive and might only become possible in later stages of the development process. Using a virtual simulation environment offers a safe possibility of testing new systems in early stages of development. Aditionally, driver-in-the-loop tests at test track and in a virtual simulator make it possible to evaluate driver reaction and potential acceptance by the future users of those systems. Within PROSPECT the new functions are investigated under various aspects in several simulator studies and test track studies. This deliverable D7.3 gives detailed information of conduction and results of the each study. Three studies focus exclusively on the for Vulnerable Road Users (VRUs) specifically dangerous urban intersection scenarios. The first of those studies examines the driver behaviour in a turning situation when a byciclist might be crossing. The described phenomena are looked-but-failed-to-see and failed-to-look. The second study, which provides an initial step in this line of research, analyzed the acceptance of issued forward collision warning times. The positioning of the potential accident opponent and the subjective feeling towards the criticality of the situation by the driver were key parameters taken into account. Last, but not least the acceptance of an intersection assist autonomous emergency braking systems was tested regarding the acceptance of potential buyers. The study was run for five days in a row for each participant to be able to judge the behaviour in a comuting situation. Two studies focused on longitudinal scenarios. Both studies followed the same design, but one was conducted on a test track and the other one in a simulator. The main objective was to investigate drivers reactions to FCW warnings and Active Steering interventions in critical VRU scenarios in case of a distraction of the driver. Additionally, the test track study was used to validate the results from the simulator study. The results of those studies are the basis for a wide acceptance evaluation of the systems. No system is an asset in increasing road safety if it is not accepted by the user and therefore turned off, if it is not required the system to be default on in consumer tests. Complemented by an additional acceptance study where the participants had to give their opinion of those systems after they watched videos of dangerous situations, the acceptance was analyzed based on questionnaires developed in PROSPECT and reported in Deliverable 7.2. This wholistic approach allows an expert discussion on the potentials of the PROSPECT functions in the future

    Results from Iowa State Female Graduate Student Needs Assessment Survey, July 2012

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    During the spring 2012 semester, a task force of graduate students, staff, and faculty created a survey to gather information from women graduate students about their experiences at Iowa State University (ISU). The survey was adapted from similar surveys at MIT and University of Maryland. Our survey had four main sections: (1) Campus climate, (2) Professional development and academic services, (3) Student workload and student services, (4) Wellness, family and housing

    Population-level effects of human papillomavirus vaccination programs on infections with nonvaccine genotypes

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    We analyzed human papillomavirus (HPV) prevalences during prevaccination and postvaccination periods to consider possible changes in nonvaccine HPV genotypes after introduction of vaccines that confer protection against 2 high-risk types, HPV16 and HPV18. Our meta-analysis included 9 studies with data for 13,886 girls and women ≤19 years of age and 23,340 women 20–24 years of age. We found evidence of cross-protection for HPV31 among the younger age group after vaccine introduction but little evidence for reductions of HPV33 and HPV45. For the group this same age group, we also found slight increases in 2 nonvaccine high-risk HPV types (HPV39 and HPV52) and in 2 possible high-risk types (HPV53 and HPV73). However, results between age groups and vaccines used were inconsistent, and the increases had possible alternative explanations; consequently, these data provided no clear evidence for type replacement. Continued monitoring of these HPV genotypes is important

    Definiteness across languages

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    Definiteness has been a central topic in theoretical semantics since its modern foundation. However, despite its significance, there has been surprisingly scarce research on its cross-linguistic expression. With the purpose of contributing to filling this gap, the present volume gathers thirteen studies exploiting insights from formal semantics and syntax, typological and language specific studies, and, crucially, semantic fieldwork and cross-linguistic semantics, in order to address the expression and interpretation of definiteness in a diverse group of languages, most of them understudied. The papers presented in this volume aim to establish a dialogue between theory and data in order to answer the following questions: What formal strategies do natural languages employ to encode definiteness? What are the possible meanings associated to this notion across languages? Are there different types of definite reference? Which other functions (besides marking definite reference) are associated with definite descriptions? Each of the papers contained in this volume addresses at least one of these questions and, in doing so, they aim to enrich our understanding of definiteness

    Definiteness across languages

    Get PDF
    Definiteness has been a central topic in theoretical semantics since its modern foundation. However, despite its significance, there has been surprisingly scarce research on its cross-linguistic expression. With the purpose of contributing to filling this gap, the present volume gathers thirteen studies exploiting insights from formal semantics and syntax, typological and language specific studies, and, crucially, semantic fieldwork and cross-linguistic semantics, in order to address the expression and interpretation of definiteness in a diverse group of languages, most of them understudied. The papers presented in this volume aim to establish a dialogue between theory and data in order to answer the following questions: What formal strategies do natural languages employ to encode definiteness? What are the possible meanings associated to this notion across languages? Are there different types of definite reference? Which other functions (besides marking definite reference) are associated with definite descriptions? Each of the papers contained in this volume addresses at least one of these questions and, in doing so, they aim to enrich our understanding of definiteness

    Definiteness across languages

    Get PDF
    Definiteness has been a central topic in theoretical semantics since its modern foundation. However, despite its significance, there has been surprisingly scarce research on its cross-linguistic expression. With the purpose of contributing to filling this gap, the present volume gathers thirteen studies exploiting insights from formal semantics and syntax, typological and language specific studies, and, crucially, semantic fieldwork and cross-linguistic semantics, in order to address the expression and interpretation of definiteness in a diverse group of languages, most of them understudied. The papers presented in this volume aim to establish a dialogue between theory and data in order to answer the following questions: What formal strategies do natural languages employ to encode definiteness? What are the possible meanings associated to this notion across languages? Are there different types of definite reference? Which other functions (besides marking definite reference) are associated with definite descriptions? Each of the papers contained in this volume addresses at least one of these questions and, in doing so, they aim to enrich our understanding of definiteness

    Definiteness across languages

    Get PDF
    Definiteness has been a central topic in theoretical semantics since its modern foundation. However, despite its significance, there has been surprisingly scarce research on its cross-linguistic expression. With the purpose of contributing to filling this gap, the present volume gathers thirteen studies exploiting insights from formal semantics and syntax, typological and language specific studies, and, crucially, semantic fieldwork and cross-linguistic semantics, in order to address the expression and interpretation of definiteness in a diverse group of languages, most of them understudied. The papers presented in this volume aim to establish a dialogue between theory and data in order to answer the following questions: What formal strategies do natural languages employ to encode definiteness? What are the possible meanings associated to this notion across languages? Are there different types of definite reference? Which other functions (besides marking definite reference) are associated with definite descriptions? Each of the papers contained in this volume addresses at least one of these questions and, in doing so, they aim to enrich our understanding of definiteness
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