Evaluation of topic-based adaptation and student modeling in QuizGuide

This paper presents an in-depth analysis of a nonconventional topic-based personalization approach for adaptive educational systems (AES) that we have explored for a number of years in the context of university programming courses. With this approach both student modeling and adaptation are based on coarse-grained knowledge units that we called topics. Our motivation for the topic-based personalization was to enhance AES transparency for both teachers and students by utilizing typical topic-based course structures as the foundation for designing all aspects of an AES from the domain model to the end-user interface. We illustrate the details of the topic-based personalization technology, with the help of the Web-based educational service QuizGuide—the first system to implement it. QuizGuide applies the topic-based personalization to guide students to the right learning material in the context of an undergraduate C programming course. While having a number of architectural and practical advantages, the suggested coarse-grained personalization approach deviates from the common practices toward knowledge modeling in AES. Therefore, we believe that several aspects of QuizGuide required a detailed evaluation—from modeling accuracy to the effectiveness of adaptation. The paper discusses how this new student modeling approach can be evaluated, and presents our attempts to evaluate it from multiple different prospects. The evaluation of QuizGuide across several consecutive semesters demonstrates that, although topics do not always support precise user modeling, they can provide a basis for successful personalization in AESs

Dissecting post-apartheid labour market developments: Decomposing a discrete choice model while dealing with unobservables

The abolition of apartheid should have improved the employment prospects of black South Africans. The reality seems to have been different, with rising unemployment rates. Disentangling the real trends from changes in measurement and sampling design has proved to be difficult. We tackle this issue by means of an new methodology for decomposing changes in a proportion. Our approach is based on a methodology presented by Lemieux for continuous variables. In particular we show how we can construct counterfactual data at the individual level controlling for unobservable effects. We show that this methodology has many attractive features when compared to other approaches available. In particular it lends itself to graphical analyses. We use this methodology to explore changes in the proportion of African men being employed, unemployed and not economically active in South Africa in the post-apartheid period. Our results suggest that changes in the characteristics of these men have made them more employable over time, but that the propensity to be employed has declined. One might say that the human and social capital of these men has improved, but that the returns on that capital have declined. The net effect has been to leave measured employment more or less static. Changes in their characteristics and in their propensity to be economically active have both worked towards increasing the participation rate. As a consequence unemployment has risen over time. The analysis confirms that there are important measurement changes between different national surveys.decomposition, discrete choice models, South Africa, employment, unemployment, participation

An Assessment of New Jersey Trout Production Systems : a Movement Towards Sustainability

New Jersey supports reproducing populations of three lotic salmonids. Only Brook Trout (Salvelinus fontinalis) are native and until approximately 100 years ago, were found in abundance throughout the northern part of the state. Presently, native populations have been documented in 115 streams or stream sections and declines are thought to be in response to anthropogenically originated environmental stressors. To evaluate the deterioration extent and assess numbers of breeding non-native Brown Trout (Salmo trutta) and Rainbow Trout (Oncorhynchus mykiss), comparisons are made between sets of historical (1968-1977) and modern (2001-2010) young-of-the-year presence/absence and abundance data and several geologic and land use/land cover characteristics hypothesized to influence species’ occurrence. The range of reproducing Brown Trout populations have expanded, while groups of Rainbow and Brook Trout, as well as the overall amount of non-trout water have all decreased slightly. Results show that land use and land cover catchment value thresholds exist at \u3c 12% agriculture, \u3c 22% barren and urban, \u3e 64% wetland and forest, and \u3c 4-6% impervious cover to allow for natural Brook Trout reproduction. Values for Brown Trout reproduction include \u3c 14% agriculture, \u3c 27% barren and urban, \u3e 58% wetland and forest, and \u3c 5-7% impervious cover. Additionally, a previously undocumented Brook Trout metapopulation has been discovered with abundance estimates suggesting that a flourishing, reproductive and viable population is being maintained. Also, observed movement between connected waters allows for gene flow and overall isolation may permit the existence of one of New Jersey’s remaining relict Brook Trout groups. Conservation of the once endemic native species has become a regional priority and a review of current lotic salmonid management strategies has identified some practices that may undermine protection efforts. Suggestions to reverse declines and bolster unique populations include: 1) establishing a ‘Wild Native’ angling regulation, 2) creating stricter land use directives to support more natural flows, 3) curtailing or cessation of domestic salmonid stocking at larger catchment levels, 4) developing hatchery operation expansion to include indigenous origin fish, 5) removal of non-native fish from favorable standing within the State’s Wildlife Action Plan, and 6) obtaining new or reallocating current funds to support more research

Comparisons Of Nutrition And Budgeting Knowledge Of Food Secure And Food Insecure Sophomores At Appalachian State University

Food insecurity means limited access to safe, nutritious food that supports a healthy life. This problem is widespread among US college students, with rates from 14% to 59%. Previously the rate at Appalachian State University (AppState) was 46.2%. This descriptive, cross-sectional study measured the food security status, nutrition and budgeting knowledge, and budgeting behaviors of food secure (FS) and food insecure (FI) sophomores attending AppState during the spring 2019 semester, and identified associations between these variables. A random sample of 1,792 sophomores received electronic recruitment letters. Data were collected with an online questionnaire. Food security status was measured using the USDA ten-item Adult Food Security Survey Module (AFSSM), nutrition, and budgeting knowledge and budgeting behaviors were measured. Correlational analyses examined associations, and statistical significance was p < 0.05. Among the 222 sophomores, 119 (53.6%) were FS and 103 (46.4%) were FI. No significant correlations existed between AFSSM scores and nutrition (r= -0.071, p= 0.320) and budgeting knowledge (r= -0.06, p=0.404), or budgeting behaviors (r= -0.08, p=0.297). A significant positive correlation emerged between budgeting behaviors and knowledge (r=0.20, p=0.010). Interventions need to teach these FS and FI sophomores to identify low-cost nutritious foods, construct a monthly budget that anticipates food costs, and use money-saving practices to purchase healthy foods