What Linear Estimators Miss: Re-Examining the Effects of Family Income on Child Outcomes

This paper uses a rich Norwegian dataset to re-examine the causal relationship between family income and child outcomes. Motivated by theoretical predictions and OLS results that suggest a nonlinear relationship, we depart from previous studies in allowing the marginal effects on children’s outcomes of an increase in family income to vary across the income distribution. Our nonlinear IV and fixed-effect estimates show an increasing, concave relationship between family income and children's educational attainment and IQ. The linear estimates, however, suggest small, if any, effect of family income, because they assign little weight to the large marginal effects at the lower part of the income distribution.instrumental variables estimation, fixed effects estimation, nonlinearities, child development, family income, linear models

Topographical scattering of waves: a spectral approach

The topographical scattering of gravity waves is investigated using a spectral energy balance equation that accounts for first order wave-bottom Bragg scattering. This model represents the bottom topography and surface waves with spectra, and evaluates a Bragg scattering source term that is theoretically valid for small bottom and surface slopes and slowly varying spectral properties. The robustness of the model is tested for a variety of topographies uniform along one horizontal dimension including nearly sinusoidal, linear ramp and step profiles. Results are compared with reflections computed using an accurate method that applies integral matching along vertical boundaries of a series of steps. For small bottom amplitudes, the source term representation yields accurate reflection estimates even for a localized scatterer. This result is proved for small bottom amplitudes $h$ relative to the mean water depth $H$. Wave reflection by small amplitude bottom topography thus depends primarily on the bottom elevation variance at the Bragg resonance scales, and is insensitive to the detailed shape of the bottom profile. Relative errors in the energy reflection coefficient are found to be typically $2h/H$.Comment: Second revision for Journal of Waterways Ports and Coastal Engineerin

On Distributed Cognition While Designing an AI System for Adapted Learning

When analyzing learning, focus has traditionally been on the teacher, but has in the recent decades slightly moved toward the learner. This is also reflected when supporting systems, both computer-based and more practical equipment, has been introduced. Seeing learning as an integration of both an internal psychological process of acquisition and elaboration, and an external interaction process between the learner and the rest of the learning environment though, we see the necessity of expanding the vision and taking on a more holistic view to include the whole learning environment. Specially, when introducing an AI (artificial intelligence) system for adapting the learning process to an individual learner through machine learning, this AI system should take into account both the learner and the other agents and artifacts being part of this extended learning system. This paper outlines some lessons learned in a process of developing an electronic textbook adapting to a single learner through machine learning, to the process of extracting input from and providing feedback both to the learner, the teacher, the learning institution, and the learning resources provider based on a XAI (explainable artificial intelligence) system while also taking into account characteristics with respect to the learner's peers

Abooks and the AIM project

During the last decades, learning has once again become a key topic. However, this time, not only for students and professors but also in political and economic contexts. One reason for this is that a high level of education and skills of nations, organizations, and individuals are considered both necessary and crucially competitive advantages in the present knowledge society and the globalized market. Therefore, obtaining a quality education is fundamental for all of us in today\u27s competitive business world. In particular, adult learning within the maritime sector has been important for the success of this industry for ages. The question now is how to streamline and facilitate the learning process for the learners, the lecturers, the authors, and the learning institutions. TERP has taken on the challenge of improving this learning process by introducing Abooks, electronic textbooks based on principles of pedagogy (the science of learning), and andragogy (the science of learning focusing on adults) that adapt to the learner through artificial intelligence. Abooks also introduces the opportunity of utilizing immersive techniques. This is being developed in the AIM project; Adapting to the Individual through Machine learning, a research project led by the research department in TERP in collaboration with the University of Stavanger and the Norwegian Computing Center

Acoustic characteristics and learner profiles of low, mid and high-level second language fluency

In the context of 90 adult Japanese learners of English with diverse L2 experience and 10 native speakers, this study examined the linguistic characteristics and learner profiles of low, mid and high-level fluency performance. The participants’ spontaneous speech samples were first rated by 10 native listeners for global fluency on a 9-point scale (1 =dysfluent, 9 = very fluent), and then divided into four proficiency groups via cluster analyses: low (n = 29), mid (n = 30), high (n = 31) and native (n = 10). Next, the dataset was analyzed for the number of pauses in mid/final clauses, articulation rate and the frequency of repetitions/self-corrections. According to the results of a series of ANOVAs, the number of final-clause pauses differentiated low and mid-level fluency performance; the number of mid-clause pauses differentiated mid and high-level performance; and articulation rate differentiated high and nativelike performance. The analyses also found that the participants’ L2 fluency was significantly associated with their length of residence profiles (0-18 years), but not with their age of arrival profiles (19-40 years)

Domestic Violence and the Mental Health and Well-being of Victims and Their Children

Almost one third of women worldwide report some form of physical or sexual violence by a partner in their lifetime, yet little is known about the mental health and well-being effects for either victims or their children. We study the costs associated with domestic violence (DV) in the context of Norway, where we can link offenders to victims and their children over time. Our difference-in-differences framework uses those who will be victimized in the future as controls. We find that a DV report involving the police is associated with large changes in the home environment, including marital dissolution and a corresponding decline in financial resources. A DV report increases mental health visits by 35% for victims and by 19% for their children in the year of the event, effects which taper off over time for the victim, but not for children. Victims also experience more doctor visits, lower employment, reduced earnings and a higher use of disability insurance while their children are more likely to receive child protective services and commit a crime. Using a complementary RD design, we find that a DV report results in declines both in children’s test scores and completion of the first year of high school

Roles of domain-general auditory processing in spoken second-language vocabulary attainment in adulthood

Recently, scholars have begun to explore the hypothesis that individual differences in domain-general auditory perception, which has been identified as an anchor of L1 acquisition, could explain some variance in postpubertal L2 learners’ segmental and suprasegmental learning in immersive settings. The current study set out to examine the generalizability of the topic to the acquisition of higher-level linguistic production skills—that is the appropriate use of diverse, rich, and abstract vocabulary. The speech of 100 Polish-English bilinguals was elicited using an interview task, submitted to corpus-/rater-based linguistic analyses, and linked to their ability to discriminate sounds based on individual acoustic dimensions (pitch, duration, and amplitude). According to the results, those who attained more advanced L2 lexical proficiency demonstrated not only more relevant experience (extensive immersion and earlier age of arrival), but also more precise auditory perception ability

Developing, Analyzing and Sharing Multivariate Datasets: Individual Differences in L2 Learning Revisited

Following the trends established in psychology and emerging in L2 research, we explain our support for an Open Science approach in this paper (i.e., developing, analyzing and sharing datasets) as a way to answer controversial and complex questions in applied linguistics. We illustrate this with a focus on a frequently debated question, what underlies individual differences in the dynamic system of post-pubertal L2 speech learning? We provide a detailed description of our dataset which consists of spontaneous speech samples, elicited from 110 late L2 speakers in the UK with diverse linguistic, experiential and sociopsychological backgrounds, rated by ten L1 English listeners for comprehensibility and nativelikeness. We explain how we examined the source of individual differences by linking different levels of L2 speech performance to a range of learner-extrinsic and intrinsic variables related to first language backgrounds, age, experience, motivation, awareness, and attitudes using a series of factor and Bayesian mixed-effects ordinal regression analyses. We conclude with a range of suggestions for the fields of applied linguistics and SLA, including the use of Bayesian methods in analyzing multivariate, multifactorial data of this kind, and advocating for publicly available datasets. In keeping with recommendations for increasing openness of the field, we invite readers to rethink and redo our analyses and interpretations from multiple angles by making our dataset and coding publicly available as part of our 40th anniversary ARAL article

Wave modelling - the state of the art

This paper is the product of the wave modelling community and it tries to make a picture of the present situation in this branch of science, exploring the previous and the most recent results and looking ahead towards the solution of the problems we presently face. Both theory and applications are considered. The many faces of the subject imply separate discussions. This is reflected into the single sections, seven of them, each dealing with a specific topic, the whole providing a broad and solid overview of the present state of the art. After an introduction framing the problem and the approach we followed, we deal in sequence with the following subjects: (Section) 2, generation by wind; 3, nonlinear interactions in deep water; 4, white-capping dissipation; 5, nonlinear interactions in shallow water; 6, dissipation at the sea bottom; 7, wave propagation; 8, numerics. The two final sections, 9 and 10, summarize the present situation from a general point of view and try to look at the future developments