Concept-level knowledge visualization for supporting self-regulated learning

Mastery Grids is an intelligent interface that provides access to different kinds of practice content for an introductory programming course. A distinctive feature of the interface is a parallel topic-level visualization of student progress and the progress of their peers. This contribution presents an extended version of the original system that features a finegrained visualization of student knowledge on the level of the detailed concepts that are associated with the course. The student model is based on a Bayesian-network which is built using students performance history in the learning activities. Copyright held by the owner/author(s)

Navigation support in complex open learner models: assessing visual design alternatives

Open Learner Models are used in modern e-learning to show system users the content of their learner models. This approach is known to prompt reflection, facilitate planning and navigation. Open Learner Models may show different levels of detail of the underlying learner model, and may structure the information differently. However, a trade-off exists between useful information and the complexity of the information. This paper investigates whether offering richer information is assessed positively by learners and results in more effective support for learning tasks. An interview pre-study revealed which information within the complex learner model is of interest. A controlled user study examined six alternative visualisation prototypes of varying complexity and resulted in the implementation of one of the designs. A second controlled study involved students interacting with variations of the visualisation while searching for suitable learning material, and revealed the value of the design alternative and its variations. The work contributes to developing complex open learner models by stressing the need to balance complexity and support. It also suggests that the expressiveness of open learner models can be improved with visual elements that strategically summarise the complex information being displayed in detail

Enriching Intelligent Textbooks with Interactivity: When Smart Content Allocation Goes Wrong

One of the main directions of increasing the educational value of a digital textbook is its enrichment with interactive content. Such content can come from outside the textbooks - from multiple existing repositories of educational resources. However, finding the right place for such external resources is not always a trivial task. There exist multiple sources of potential problems: from mismatching metadata to mutually contradicting prerequisite-outcome structures of underlying resources, from differences in granularity and coverage to ontological conflicts. In this paper, we make an attempt to categorize these problems and give examples from our recent experiment on automated assignment of smart interactive learning content to the chapters of an intelligent textbook in a programming domain

Precise measurement of the W-boson mass with the CDF II detector

We have measured the W-boson mass MW using data corresponding to 2.2/fb of integrated luminosity collected in proton-antiproton collisions at 1.96 TeV with the CDF II detector at the Fermilab Tevatron collider. Samples consisting of 470126 W->enu candidates and 624708 W->munu candidates yield the measurement MW = 80387 +- 12 (stat) +- 15 (syst) = 80387 +- 19 MeV. This is the most precise measurement of the W-boson mass to date and significantly exceeds the precision of all previous measurements combined

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum