Speededness in Achievement Testing: Relevance, Consequences, and Control

Da Prüfungen und Tests häufig dazu dienen, den Zugang zu Bildungsprogrammen zu steuern und die Grundlage zur Abschlussvergabe am Ende von Bildungsprogrammen bilden, ist ihre Fairness und Validität von größter Bedeutung. Ein kontrovers diskutierter Aspekt standardisierter Tests ist die Verwendung von Zeitlimits. Unabhängig davon ob eine Testadministration Zeitdruck hervorrufen soll oder nicht, sollten Testentwickler:innen in die Lage versetzt werden, den Zeitdruck einer Testadministrationen explizit gestalten zu können. Zu diesem Zweck schlägt van der Linden (2011a, 2011b) einen Ansatz zur Kontrolle des Zeitdrucks von Tests in der automatisierten Testhefterstellung (ATA) unter Verwendung von Mixed Integer Linear Programming und eines lognormalen Antwortzeitmodells vor. Dabei hat der Ansatz von van der Linden jedoch eine zentrale Limitation: Er ist auf das zwei-parametrische lognormale Antwortzeitmodell beschränkt, das gleiche Geschwindigkeits-Sensitivitäten (d.h. Faktorladungen) für alle Items annimmt. Diese Arbeit zeigt, dass ansonsten parallele Testhefte mit unterschiedlichen Geschwindigkeits-Sensitivitäten für bestimmte Testteilnehmende unfair sind. Darüber hinaus wird eine Erweiterung des van der Linden-Ansatzes vorgestellt, die unterschiedliche Geschwindigkeits-Sensitivitäten von Items in ATA berücksichtigt. Weiter wird diskutiert, wie Testhefte mit identischen, aber unterschiedlich angeordneten Items zu Fairness-Problemen aufgrund von Item-Positionseffekten führen können und wie dies verhindert werden kann. Die vorliegende Arbeit enthält zusätzlich Anleitungen zur Verwendung des R-Pakets eatATA für ATA und zur Verwendung von Stan und rstan für Bayesianische hierarchische Antwortzeitmodellierung. Abschließend werden Alternativen, praktische Implikationen und Grenzen der vorgeschlagenen Ansätze diskutiert und Vorschläge für zukünftige Forschungsthemen gemacht.As examinations and assessments are often used to control access to educational programs and to assess successful participation in an educational program, their fairness and validity is of great importance. A controversially discussed aspect of standardized tests is setting time limits on tests and how this practice can result in test speededness. Regardless of whether a test should be speeded or not, being able to deliberately control the speededness of tests is desirable. For this purpose, van der Linden (2011a, 2011b) proposed an approach to control the speededness of tests in automated test assembly (ATA) using mixed integer linear programming and a lognormal response time model. However, the approach by van der Linden (2011a, 2011b) has an important limitation, in that it is restricted to the two-parameter lognormal response time model which assumes equal speed sensitivities (i.e., factor loadings) across items. This thesis demonstrates that otherwise parallel test forms with differential speed sensitivities are indeed unfair for specific test-takers. Furthermore, an extension of the van der Linden approach is introduced, which incorporates speed sensitivities in ATA. Additionally, test speededness can undermine the fairness of a test if identical but differently ordered test forms are used. To prevent that the score of test-takers depends on whether easy or difficult items are located at the end of a test form, it is proposed that the same, most time intensive items should be placed at the end of all test forms. The thesis also provides introductions and tutorials on using the R package eatATA for ATA and using Stan and rstan for Bayesian hierarchical response time modeling. Finally, the thesis discusses alternatives, practical implications, and limitations of the proposed approaches and provides an outlook on future related research topics

Considering Future Sea Level Change in Maritime Infrastructure Design: A Survey of US Engineers

Seaports are particularly vulnerable to coastal hazards such as hurricanes and flooding due to their location. Sea level change (SLC) can magnify the impacts of these coastal hazards, threatening the resilience of ports. Engineers must design port infrastructure that is adequately prepared for the amount of SLC expected within the design life of the structure. However, the uncertainty of SLC projections coupled with the long service lives of port infrastructure presents unique challenges to do so. Through an online survey of 85 US port and maritime infrastructure engineers, this research reflects the US engineering community\u27s attitude and approach to planning for SLC for maritime infrastructure projects. Only 29% of respondents indicated that their organization had an internal SLC policy, design, or planning document. Furthermore, results show that the lack of regulatory design standards in this area leads to engineers and their clients disregarding SLC more frequently. There is a clear need for collaboration among stakeholders to develop practical design methods for designing resilient port infrastructure

Automation and Optimization of Working Speed and Depth in Agricultural Soil Tillage with a Model Predictive Control based on Machine Learning

While facing environmental challenges due to climate change, the need for optimization and automation of agricultural tasks is increasing. Furthermore, costs and the lack of qualified personnel require efficient and highly automated control systems for agricultural machinery. Therefore, this work addresses these challenges by optimizing the working speed of a tractor and soil tillage implement combination to maintain efficient operating points during high power demands. A system was developed that predicts a suitable working speed based on a draft force and traction model in combination with the usage of a neural network for fuel rate prediction. The machine operator is able to customize optimization parameters such as fuel efficiency, performance or total costs depending on the individual needs and situation. These parameters lead to a reward function to value the machines state. Based on these objectives the network is able to predict the system state for various potential target speeds and evaluate their optimization parameters to select the most promising target speed. This target speed gets received by the tractor and leads to a new machine state. The fuel rate prediction network is trained on previously collected training data. Using different methods, for example transfer learning, the network can be adapted easily to different sizes and types of tractors. As the draft force models are based on equations, they can be changed to adapt to turning and no-turning soil tillage. To maintain a sufficient working quality and simplify online parametrization of draft force requirements, the implement working depth is automatically adjusted based on active Lidar measurements. The adjustments take the working conditions and agricultural requirements into account. The system was validated during field measurements on different locations with various customized optimization parameters. The results show a suitable reaction to changing operating conditions

Bayesian hierarchical response time modelling—A tutorial

Response time modelling is developing rapidly in the field of psychometrics, and its use is growing in psychology. In most applications, component models for response times are modelled jointly with component models for responses, thereby stabilizing estimation of item response theory model parameters and enabling research on a variety of novel substantive research questions. Bayesian estimation techniques facilitate estimation of response time models. Implementations of these models in standard statistical software, however, are still sparse. In this accessible tutorial, we discuss one of the most common response time models—the lognormal response time model—embedded in the hierarchical framework by van der Linden (2007). We provide detailed guidance on how to specify and estimate this model in a Bayesian hierarchical context. One of the strengths of the presented model is its flexibility, which makes it possible to adapt and extend the model according to researchers' needs and hypotheses on response behaviour. We illustrate this based on three recent model extensions: (a) application to non-cognitive data incorporating the distance-difficulty hypothesis, (b) modelling conditional dependencies between response times and responses, and (c) identifying differences in response behaviour via mixture modelling. This tutorial aims to provide a better understanding of the use and utility of response time models, showcases how these models can easily be adapted and extended, and contributes to a growing need for these models to answer novel substantive research questions in both non-cognitive and cognitive contexts.Peer Reviewe

ARCADE 3D-audio codec: an implementation for the web

This poster introduces the implementation of the ARCADE 3D audio codec for web browsers. ARCADE can embed a full 3D audio scene in a simple stereo-compatible audio stream that can be further compressed with standard lossy compression schemes, aired to analog or digital radio receivers or even stored on analog supports. An ARCADE-encoded stream can be decoded to any 2D or 3D-audio rendering format, for instance using Vector-Based Amplitude Panning (VBAP), Higher Order Ambisonics (HOA), or personalized binaural with head tracking. ARCADE adapts seamlessly to the audio industry needs, from storage to production, distribution/delivery, and rendering. It finds uses in Virtual or Augmented Reality (VR/AR), movies, gaming, music, telepresence & teleconferencing. We present a JavaScript (JS) and Web Audio API implementation of the ARCADE decoder, which was originally written in C++11, along with technical details of the porting operations. Live demos of 3D-audio content transmission, decoding and dynamic binaural rendering will be given during the poster session