COGNITIVE LOAD THEORY AND THE USE OF WORKED EXAMPLES AS AN INSTRUCTIONAL STRATEGY IN PHYSICS FOR DISTANCE LEARNERS: A PRELIMINARY STUDY

This article revisits the cognitive load theory to explore the use of worked examples to teach a selected topic in a higher level undergraduate physics course for distance learners at the School of Distance Education, Universiti Sains Malaysia. With a break of several years from receiving formal education and having only minimum science background, distance learners need an appropriate instructional strategy for courses that require complex conceptualization and mathematical manipulations. As the working memory is limited, distance learners need to acquire domain specific knowledge in stages to lessen cognitive load. This article charts a learning task with a lower cognitive load to teach Fermi-Dirac distribution and demonstrates the use of sequential worked examples. Content taught in stages using worked examples can be presented as a form of didactic conversation to reduce transactional distance. This instructional strategy can be applied to similar challenging topics in other well-structured domains in a distance learning environment

Molecular dynamics simulations and photoluminescence measurements of annealed ZnO surfaces

The effect of thermal annealing on wurtzite ZnO, terminated by two surfaces, (0 0 0 $\bar 1$) (which is oxygen-terminated) and (0 0 0 1) (which is Zn-terminated), is investigated via molecular dynamics simulation using reactive force field (ReaxFF). As a result of annealing at a threshold temperature range of 700~K < T_{\mbox{\small t}} \leq 800~K, surface oxygen atoms begin to sublimate from the (0 0 0 $\bar 1$) surface, while no atom leaves the (0 0 0 1) surface. The ratio of oxygen leaving the surface increases with temperature $T$ (for T \geq T_{\mbox{\small t}}). The relative luminescence intensity of the secondary peak in the photoluminescence (PL) spectra, interpreted as a measurement of amount of vacancies on the sample surfaces, qualitatively agrees with the threshold behavior as found in the MD simulations. Our simulations have also revealed the formation of oxygen dimers on the surface and evolution of partial charge distribution during the annealing process. Our MD simulation based on the ReaxFF is consistent with experimental observations.Comment: 26 pages, 11 figures. Manuscript submitted to Physica

Urban Malaysian Adolescents' Online Activities.

Many Malaysian adolescents are immersed in the global contemporary,technological and digital culture. Their everyday literacy practices involve participation in a range of activities on the Internet

The Video Cenferencing Learning Environment In Distance Education A Study Of The Interaction Pattern.

This article reports on the study undertaken to elucidate the pattern of interactions in the Video Conferencing Learning Environment (VCLE) used as a course delivery mechanism in distance learning

Kesan Pembelajaran Konstruktivisme Berasaskan Laman Web Di Kalangan pelajar-Fizik Universiti Sains Malaysia.

Artikel ini melaporkan tentang pembangunan laman Web mengikut teori konstruktivisme yang berdasarkan model .- Black & McClintock untuk kursus Fizik pra siswazah di Universiti Sains Malaysia (USM) dan juga kajian persepsi terhadap proses pembelajaran yang berlaku setelah pelajar dikenakan rawatan menggunakan laman Web yang dibina

Fundamental analysis of semiconductor-metal transition in indium-doped zinc oxide using carrier concentration and current-voltage measurements.

Transparent conducting oxides in the form of metal-doped ZnO thin films have important applications in optoelectronic devices. In this work, In-doped ZnO thin films were synthesized by magnetron sputtering using targets with different wt% (1 - 7%) of In20~ at a substrate temperature of 150°C on quartz and Si substrates

Determination of acceptor concentration, depletion width, donor level movement and sensitivity factor of ZnO on diamond heterojunction under UV illumination.

The concentration of acceptor carriers, depletion width, magnitude of donor level movement as well as the sensitivity factor are determined from the UV response of a heterojunction consisting of ZnO on type IIb diamond. From the comparison of the I-V measurements in dark condition and under UV illumination we show that the acceptor concentration (∼10(17) cm(-3)) can be estimated from p-n junction properties. The depletion width of the heterojunction is calculated and is shown to extend farther into the ZnO region in dark condition. Under UV illumination, the depletion width shrinks but penetrates both materials equally. The ultraviolet illumination causes the donor level to move closer to the conduction band by about 50 meV suggesting that band bending is reduced to allow more electrons to flow from the intrinsically n-type ZnO. The sensitivity factor of the device calculated from the change of threshold voltages, the ratio of dark and photocurrents and identity factor is consistent with experimental data