Preparing Students for Success on Examinations: Readiness Assurance Tests in a Graduate-Level Statistics Course

Formative feedback is one way to foster students' readiness for statistics examinations. The use of Readiness Assurance Tests was examined as an educational intervention in which feedback was provided for both correct and incorrect responses in a graduate-level statistics course. Examination scores in the intervention group ( n = 56) were compared with those in a control group ( n = 42). Intervention group examination scores significantly improved from 75.92 ± 14.52 on the Readiness Assurance Test to 90.06 ± 7.06, p < .001, on the midterm, and final examination scores improved from 78.23 ± 17.29 to 85.6 ± 6.98, p = .002. Intervention group midterm scores were significantly higher than those of the control group (90.06 ± 7.06 versus 79.7 ± 11.6, p < .001); however, no differences were found between the groups on the final examination (85.35 ± 9.46 versus 85.6 ± 6.98, p = .91). Use of Readiness Assurance Tests was an effective modality to increase student self-efficacy, learning experience, and, relative to a control group, midterm examination performance in statistic

Susceptibility Inhomogeneity and Non-Fermi-Liquid Behavior in Ce(Ru_{0.5}Rh_{0.5})_2Si_2

Magnetic susceptibility and muon spin rotation (\muSR) experiments have been carried out to study the effect of structural disorder on the non-Fermi-liquid (NFL) behavior of the heavy-fermion alloy Ce(Ru_{0.5}Rh_{0.5})_2Si_2. Analysis of the bulk susceptibility in the framework of disorder-driven Griffiths-phase and Kondo-disorder models for NFL behavior yields relatively narrow distributions of characteristic spin fluctuation energies, in agreement with \muSR linewidths that give the inhomogeneous spread in susceptibility. \muSR and NMR data both indicate that disorder explains the "nearly NFL" behavior observed above \sim2 K, but does not dominate the NFL physics found at low temperatures and low magnetic fields.Comment: 6 pages, 4 figures, REVTeX, submitted to Phys. Rev.

Disorder, inhomogeneity and spin dynamics in f-electron non-Fermi liquid systems

Muon spin rotation and relaxation ($\mu$SR) experiments have yielded evidence that structural disorder is an important factor in many f-electron-based non-Fermi-liquid (NFL) systems. Disorder-driven mechanisms for NFL behaviour are suggested by the observed broad and strongly temperature-dependent $\mu$SR (and NMR) linewidths in several NFL compounds and alloys. Local disorder-driven theories (Kondo disorder, Griffiths-McCoy singularity) are, however, not capable of describing the time-field scaling seen in muon spin relaxation experiments, which suggest cooperative and critical spin fluctuations rather than a distribution of local fluctuation rates. A strong empirical correlation is established between electronic disorder and slow spin fluctuations in NFL materialsComment: 24 pages, 15 figures, submitted to J. Phys.: Condens. Matte

Knight Shift Anomalies in Heavy Electron Materials

We calculate non-linear Knight Shift $K$ vs. susceptibility $\chi$ anomalies for Ce ions possessing local moments in metals. The ions are modeled with the Anderson Hamiltonian and studied within the non-crossing approximation (NCA). The $K-vs.- \chi$ non-linearity diminishes with decreasing Kondo temperature $T_0$ and nuclear spin- local moment separation. Treating the Ce ions as an incoherent array in CeSn$_3$, we find excellent agreement with the observed Sn $K(T)$ data.Comment: 4 pages, Revtex, 3 figures available upon request from [email protected]

Microscopic evidence for field-induced magnetism in CeCoIn5_5

We present NMR data in the normal and superconducting states of CeCoIn$_5$ for fields close to $H_{\rm c2}(0)=11.8$ T in the $ab$ plane. Recent experiments identified a first-order transition from the normal to superconducting state for $H> 10.5$ T, and a new thermodynamic phase below 290 mK within the superconducting state. We find that the Knight shifts of the In(1), In(2) and the Co are discontinuous across the first-order transition and the magnetic linewidths increase dramatically. The broadening differs for the three sites, unlike the expectation for an Abrikosov vortex lattice, and suggests the presence of static spin moments in the vortex cores. In the low-temperature and high-field phase the broad NMR lineshapes suggest ordered local moments, rather than a long wavelength quasiparticle spin density modulation expected for an FFLO phase.Comment: 4 pages, 4 figures. to appear in Phys. Rev. Let

Magnetic transition and spin fluctuations in the unconventional antiferromagnetic compound Yb3Pt4

Muon spin rotation and relaxation measurements have been carried out on the unconventional antiferromagnet Yb_3Pt_4. Oscillations are observed below T_N = 2.22(1) K, consistent with the antiferromagnetic (AFM) Neel temperature observed in bulk experiments. In agreement with neutron diffraction experiments the oscillation frequency omega_ mu(T) follows a S = 1/2 mean-field temperature dependence, yielding a quasistatic local field 1.71(2) kOe at T = 0. A crude estimate gives an ordered moment of ~0.66 mu_B at T = 0, comparable to 0.81 mu_B from neutron diffraction. As T approaches T_N from above the dynamic relaxation rate lambda_d exhibits no critical slowing down, consistent with a mean-field transition. In the AFM phase a T-linear fit to lambda_d(T), appropriate to a Fermi liquid, yields highly enhanced values of lambda_d/T and the Korringa constant K_ mu^2 T/lambda_d, with K_ mu the estimated muon Knight shift. A strong suppression of lambda_d by applied field is observed in the AFM phase. These properties are consistent with the observed large Sommerfeld-Wilson and Kadowaki-Woods ratios in Yb_3Pt_4 (although the data do not discriminate between Fermi-liquid and non-Fermi-liquid states), and suggest strong enhancement of q ~ 0 spin correlations between large-Fermi-volume band quasiparticles in the AFM phase of Yb_3Pt_4.Comment: 11 pages, 4 figures, submitted to J. Phys.: Condens. Matter special issue for SCES1

Playing for high stakes: Findings from the Irish neighbourhood play research project and their implications for education

The Irish Neighbourhood Play Research Project included almost 1700 families and 240 communities throughout Ireland. The findings hold clear implications for educational policy and practice. Using surveys, interviews and naturalistic observation, data was secured on how children in modern Ireland aged 0 - 15 are playing. An all-island approach was taken incorporating cities, towns and rural areas across a variety of socio-economic groupings. Interesting findings arose from the data relating to generational differences in levels of freedom, play, exercise, engagement with risk, with nature, with scheduled/timetabled extracurricular activities, with homework, with electronics, with creative activities and with traditional play types and games. Differences in play choices and experiences were also evident across socio-economic groupings, community types, gender lines, age ranges and housing types. This paper presents the data and asks what it means within a framework of educational implication. Most importantly: what can education do to redress these implications? Innovations in pedagogy and policy are required to meet the educational challenges implicit within this data. This ground breaking research on the changing face of childhood points clearly to the need for collaborative, co- participative, democratic, empowering and playful pedagogies and educational policies which support them