Effects of Using Graphic Calculators in the Teaching and Learning of Mathematics on Students’ Performance and Metacognitive Awareness

Three phases of quasi-experimental study with non-equivalent control group posttest only design were conducted to investigate the effects of using graphing calculators in mathematics teaching and learning on Form Four Malaysian secondary school students’ performance and their level of metacognitive awareness. Experiment in Phase I was conducted for two weeks to provide an initial indicator of the effectiveness of graphing calculator strategy on students’ performance and their metacognitive awareness. Graphing calculator strategy refers to the use of TI-83 Plus graphing calculator in teaching and learning of Straight Lines topic. The first phase involved one experimental group (n=21) and one control group (n=19) from two Form Four classes in a randomly selected school in Selangor. The experimental group underwent learning using graphing calculator while the control group underwent learning using conventional instruction. Experiment for Phase II was further carried out for six weeks incorporating measures of mathematical performance, focused on metacognitive awareness during problem solving and in addition, measures of mental effort and instructional efficiency. This phase involved two experimental groups (n=33) and two control groups (n=32) from four Form Four classes in one randomly selected school in Malacca. As in Phase I, the same learning conditions were given for both experimental and control groups. Finally, experiment in Phase III was carried out for six weeks incorporating comparison on two levels of mathematics ability (low and average) and two types of instructional strategy (graphing calculator strategy and conventional instruction strategy). Form Four students from one of schools in Malacca were the sample for Phase III. Altogether there were four groups of students given four learning conditions vis-à-vis: the average mathematical ability given the use of graphing calculators (n=15), the low mathematical ability also given graphing calculators (n=19), the average mathematical ability given the conventional instruction (n=16) and the low mathematical ability given also the conventional instruction (n=20).Four instruments were used in this study namely, Straight Lines Achievement Test, Paas Mental Effort Rating Scale, Metacognitive Awareness Survey and Graphing Calculator Usage Survey. The data for Phases I and II were analysed using independent t-test and planned comparison test while data for Phase III were analysed using multiple analysis of variance and planned comparison test. The study shows that the graphing calculator instruction enhanced students’ performance and induced higher levels of their metacognitive awareness with less mental effort invested during the learning and test phases and hence increased 3-dimensional instructional efficiency index in learning of Straight Lines topic for both groups of low and average mathematics ability. These findings indicated that the graphing calculator instruction is superior in comparison to the conventional instruction, hence implying that integrating the use of graphing calculator in teaching and learning of mathematics was more efficient than the conventional instruction strategy. The average mathematics ability group benefited more from the graphing calculator instruction as it decreased the amount of mental effort by double than the low mathematics ability group. Further, most students in graphing calculator strategy group showed an overall favourable view towards integrating the use of the graphing calculator in the teaching and learning of mathematics. Even though some students experience difficulties in using graphing calculators initially during learning, they responded overwhelmingly that graphing calculator improves their understanding of the Straight Lines topic and hence, the usage of the graphing calculator was an effective strategy in teaching and learning of mathematics

Quantum Criticality in Heavy Fermion Metals

Quantum criticality describes the collective fluctuations of matter undergoing a second-order phase transition at zero temperature. Heavy fermion metals have in recent years emerged as prototypical systems to study quantum critical points. There have been considerable efforts, both experimental and theoretical, which use these magnetic systems to address problems that are central to the broad understanding of strongly correlated quantum matter. Here, we summarize some of the basic issues, including i) the extent to which the quantum criticality in heavy fermion metals goes beyond the standard theory of order-parameter fluctuations, ii) the nature of the Kondo effect in the quantum critical regime, iii) the non-Fermi liquid phenomena that accompany quantum criticality, and iv) the interplay between quantum criticality and unconventional superconductivity.Comment: (v2) 39 pages, 8 figures; shortened per the editorial mandate; to appear in Nature Physics. (v1) 43 pages, 8 figures; Non-technical review article, intended for general readers; the discussion part contains more specialized topic

Lorentz violation effects on astrophysical propagation of very high energy photons

Lorentz violation (LV) is predicted by some quantum gravity (QG) candidates, wherein the canonical energy-momentum dispersion relation, $E^2=p^2+m^2$, is modified. Consequently, new phenomenons beyond the standard model are predicted. Especially, the presence of LV highly affects the propagation of astrophysical photons with very high energies from distant galaxies. In this paper, we review the updating theoretical and experimental results on this topic. We classify the effects into three categories: (i) time lags between photons with different energies; (ii) a cutoff of photon flux above the threshold energy of photon decay, $\gamma \rightarrow e^++e^-$; (iii) new patterns in the spectra of multi-TeV photons and EeV photons, due to the absorption of background lights. As we can see, the details of LV effects on astrophysical photons depend heavily on the "phase space" of LV parameters. From observational aspects, nowadays available and upcoming instruments can study these phenomenons hopefully, and shed light onto LV issues and QG theories. The most recent progresses and constraints on the ultra-high energy cosmic rays (UHECRs) are also fully discussed.Comment: 9 pages, 1 figure, final version for publication in MPLA as a review articl

Pengembangan Modul Matematika Untuk Pembelajaran Berbasis Masalah (Problem Based Learning) Pada Materi Pokok Persamaan Garis Lurus Kelas VIII SMP

Absrtact:The objectives of this research were to investigate: (1) how to develop of Mathematics module development for problem-based learning on the topic of discussion of Linear Equation of Straight Line for Grade VIII of Junior Secondary School; and (2) the effectiveness of result of Mathematics module development for problem-based learning on the topic of discussion of Linear Equation of Straight Line for Grade VIII of Junior Secondary School. This research consisted of two phases. The first phase was the phase for development and stipulation of a module as a product of research and development. It included preliminary study, module development, module validation, focus group discussion, product testing, and revision. The second phase was the phase of module effectiveness testing with the quasi experimental research with the factorial design of 2x1. The population of research was the students in Grade VIII of Junior Secondary Schools in Yogyakarta City. Sample consisted of students of SMP N 5 Yogyakarta and SMP N 2 Yogyakarta. The data of research were gathered through observation, unstructured interview, questionnaire, and test of learning result. They were then analyzed by using the descriptive quantitative analysis. Based on the result of the analysis, we can conclude that: 1) development of Mathematics module for problem-based learning on the topic of discussion of Linear Equation of Straight Line for Grade VIII of Junior Secondary School includes preliminary study, module drafting, module validation, module revision I,focus group discussion, module revision II, initial field testing, module revision III, field testing or module effectiveness testing, module revision IV (Finalizing the final product). The result of development in this research was Mathematics module for problem-based learning on the topic of discussion of Equation of Straight Line for Grade VIII of Junior Secondary School. 2) The result of module effectiveness testing shows that Mathematics module for problem-based learning on the topic of discussion of Linear Equation of Straight Line for Grade VIII of Junior Secondary School is proven to be effective

Inter-organizational communities of practice: specificities and stakes

Inter-organizational communities of practice (IOCoPs) are today an emergent research topic and studies in this area are still in an exploratory phase. Theoretical mechanisms are vaguely specified and empirical studies are incipient. For this reason, this paper firstly aims at presenting the specificities and stakes of such organizational forms, establishing reference points for further research in this field. We will introduce the main features of IOCoPs and explain why they do not represent a mere subcategory of CoPs, but a unit of analysis per se. In this paper, we will follow a thematic approach to indicate IOCoPs’ specificities and stakes. We will thus look at the IOCoPs’ actors (in part I), IOCoPs as original organizational forms (part II), then IOCoPs’ life cycle (part III). Finally, we will synthesize IOCoPs’ distinctive features and conclude with a discussion on key interests of IOCoPs for both practitioners and academics.Community of practice; inter-organizational relationships; professional practice; expertise; knowledge management; learning; organizational boundaries; life-cycle