International assessment of low reading proficiency in the adult population: A question of components or lower rungs?

Practice engagement theory (PET) posits that individuals' literacy proficiencies develop as a by-product of their engagement in everyday reading and writing practices and, reciprocally, that literacy proficiencies affect levels of engagement in reading and writing practices. This suggests that literacy training which increases engagement in meaningful practices might generate proficiency growth. Research has shown that this approach does indeed seem to be effective in improving (adult) learners' literacy proficiency. A number of cross-sectional comparisons of participants' and non-participants' performance in various training activities, as well as quantitative modelling of adults' proficiency growth in longitudinal studies have confirmed the theoretical assumptions of PET. The authors of this article describe the first application of PET to literacy and numeracy development in a longitudinal study of a nationally representative adult population. Their investigation followed a sample of adults initially interviewed and assessed in the German component of the Programme for the International Assessment of Adult Competencies (PIAAC), adding longitudinal data from three additional waves of the national extension study (PIAAC-L), which included repeated assessments of literacy and numeracy proficiency over a period of three years. The authors’ quantitative modelling of the growth of literacy and numeracy proficiency over time provides strong support for PET. Their comparisons of how various practice engagement indexes predict growth of literacy and numeracy proficiencies indicate that reading engagement is the strongest predictor of literacy growth and maths engagement is the strongest predictor of numeracy growth. The authors conclude their article by considering their findings’ implications for sustainable development, lifelong learning policy and future research into the development of adult literacy and numeracy proficiency

Performance analysis of sequential carrier- and code-tracking receivers in the context of high-precision space-borne metrology systems

Future space observatories achieve detection of gravitational waves by interferometric measurements of a carrier phase, allowing to determine relative distance changes, in combination with an absolute distance measurement based on the transmission of pseudo-random noise chip sequences. In addition, usage of direct-sequence spread spectrum modulation enables data transmission. Hereafter, we report on the findings of a novel performance evaluation of planned receiver architectures, performing phase and distance readout sequentially, addressing the interplay between both measurements. An analytical model is presented identifying the power spectral density of the chip modulation at frequencies within the measurement bandwidth as the main driver for phase noise. This model, verified by numerical simulations, excludes binary phase-shift keying modulations for missions requiring pico-meter noise levels at the phase readout, while binary offset carrier modulation, where most of the power has been shifted outside the measurement bandwidth, exhibits superior phase measurement performance. Ranging analyses of the delay-locked loop reveal strong distortion of the pulse shape due to the preceding phase tracking introducing ranging bias variations. Numerical simulations show that these variations, however, which originate from data transitions, are compensated by the delay tracking loop, enabling sub-meter ranging accuracy, irrespective of the modulation type.Comment: 10 pages, 6 figure

Compensation of front-end and modulation delays in phase and ranging measurements for time-delay interferometry

In the context of the Laser Interferometer Space Antenna (LISA), the laser subsystems exhibit frequency fluctuations that introduce significant levels of noise into the measurements, surpassing the gravitational wave signal by several orders of magnitude. Mitigation is achieved via time-shifting individual measurements in a data processing step known as time-delay interferometry (TDI). The suppression performance of TDI relies on accurate knowledge and consideration of the delays experienced by the interfering lasers. While considerable efforts have been dedicated to the accurate determination of inter-spacecraft ranging delays, the sources for onboard delays have been either neglected or assumed to be known. Contrary to these assumptions, analog delays of the phasemeter front end and the laser modulator are not only large but also prone to change with temperature and heterodyne frequency. This motivates our proposal for a novel method enabling a calibration of these delays on-ground and in-space, based on minimal functional additions to the receiver architecture. Specifically, we establish a set of calibration measurements and elucidate how these measurements are utilized in data processing, leading to the mitigation of the delays in the TDI Michelson variables. Following a performance analysis of the calibration measurements, proposed calibration scheme is assessed through numerical simulations. We find that in the absence of the calibration scheme, the assumed drifts of the analog delays increase residual laser noise at high frequencies of the LISA measurement band. A single, on-ground calibration of the analog delays leads to an improvement by roughly one order of magnitude, while re-calibration in space may improve performance by yet another order of magnitude. Towards lower frequencies, ranging error is always found to be the limiting factor for which countermeasures are discussed.Comment: 14 pages, 6 figure

Bildungspolitische Konsequenzen (inter-)nationaler Vergleichsstudien zur Literalitätskompetenz: zur Relevanz der Bestimmung eines Mindestniveaus in der Alphabetisierung

Das Thema Literalität Erwachsener hat nicht zuletzt aufgrund der in den letzten Jahren durchgeführten OECD-Vergleichsstudien IALS, ALL und PIAAC auf internationaler und nationaler Ebene an Bedeutung gewonnen. Die Folge war eine Reihe von bildungspolitischen Entwicklungen, insbesondere bezüglich der Forderung und Finanzierung von Literalität. Der vorliegende Beitrag gibt anhand von Länderberichten einen international-vergleichenden Einblick in die hierzu geführte Diskussion seit der IALS-Studie. Daran anschließend wird unter Bezugnahme auf die Ergebnisse der leo.-GER-Verlinkungsstudie speziell für Deutschland die Frage diskutiert, bis zu welchem Kompetenzniveau Literalität in angemessener Weise zu fordern sei