Collaboration in an Asynchronous Online Educator Preparation Program

Asynchronous online courses generally provide little opportunity for students to collaborate with peers. In a typical asynchronous course, students work fairly independently and the main interaction with peers is in discussion forums. Yet, professional standards for teachers and school leaders recognize collaborating with stakeholders as a significant responsibility (InTASC, 2013; Professional Standards for Education Leaders, 2015). Acknowledging this, we wanted to provide candidates with an authentic experience communicating and working in teams, and simultaneously make their online coursework more interactive. This paper and presentation will focus on how faculty in an asynchronous online education program addressed this problem of practice. It will also describe the steps taken to identify and redesign assignments that could become collaborative projects in place of independent student work. The results of several semesters of feedback from students who were required to work in collaborative teams to complete assignments will be presented

Using Screen Recording Tools to Increase Instructor Presence in Online Courses

Introduction Even with the volume of text-based communication that is common in online courses, students and instructors frequently report a feeling of isolation. This may be partly due to the lack of visual and audio cues that naturally occur in a traditional classroom. Screen recording technologies provide a way to increase presence as they can offer the opportunity to see and hear the instructor. Screen recording technologies are readily available, easy-to-use, web-based tools that can positively impact instructor-student connections, improve student satisfaction, and increase instructor presence. Instructor presence is indicated as a best practice for online teaching and learning. A six-semester study provides evidence of the effectiveness of using screen recordings to address these issues

Feedback in Online Courses: An Essential Instructional Practice

As institutions of higher education turn more to online and remote learning, the ability of faculty to provide actionable feedback to students remains a critical responsibility of effective instructors. Based on a review of research on the significance of feedback to student learning and a review of online courses over the past several semesters, it was determined that there are significant differences in the timeliness, methods, frequency, and quality of feedback given to students. The variability noted can alter the impact on student learning. Based on their experience as online instructors the writers suggest best practices for providing feedback that that have proven successful in practice

Etching of Si through a thick condensed XeF2 layer

Etching of silicon by XeF2 is studied in a multiple-beam setup. Below 150 K XeF2 condenses and forms a layer on the silicon, which blocks the etching. Upon ion bombardment, this layer is removed and etching will resume. As a function of the layer thickness, the various removal mechanisms of the layer are studied. For a thick condensed layer it is found that 1 keV Ar+ ions sputter the condensed layer with a yield of 160 XeF2 molecules per ion for 1 keV Ar+ ions and 280 for 2 keV ions. For thinner layers (below 9 nm for 1 keV ions), this sputter rate by ions decreases significantly. Here, the removal is mainly due to consumption of XeF2 by etching at the bottom of the layer. This consumption rate reaches a maximum for a layer thickness of about 5 nm. In the steady-state situation, the layer thickness is further decreased, resulting in a smaller consumption and etch rate. Here, sputtering is the most important removal mechanism for the deposited XeF2 layer. From this, it is concluded that a pulsed ion beam should be used in cryogenic etching to obtain the highest etch rate

An intense, slow and cold beam of metastable Ne(3s) ^3P_2 atoms

We employ laser cooling to intensify and cool an atomic beam of metastable Ne(3s) atoms. Using several collimators, a slower and a compressor we achieve a ^{20}Ne^* flux of 6 10^{10} atoms/s in an 0.7 mm diameter beam traveling at 100 m/s, and having longitudinal and transverse temperatures of 25mK and 300microK, respectively. This constitutes the highest flux in a concentrated beam achieved to date with metastable rare gas atoms. We characterize the action of the various cooling stages in terms of their influence on the flux, diameter and divergence of the atomic beam. The brightness and brilliance achieved are 2.1 10^{21} s^{-1} m^{-2} sr^{-1} and 5.0 10^{22} s^{-1} m^{-2} sr^{-1}, respectively, comparable to the highest values reported for alkali-metal beams. Bright beams of the ^{21}Ne and ^{22}Ne isotopes have also been created.Comment: 18 pages, 9 figures, RevTe

Silicon etch rate enhancement by traces of metal

We report the effect of nickel and tungsten contamination on the etch behavior of silicon. This is studied in a molecular beam setup, where silicon is etched by XeF2 and Ar+ ions. The etch process is directly monitored by the SiF4 reaction products which leave the surface. The effect of contamination appears very pronounced after the ion beam is switched off: it leads to a temporary enhancement of the spontaneous etch rate on a time scale of 500 s. With traces of contamination on the order of 0.01 ML, the etch rate may be enhanced by a factor of 2 for W and somewhat less for Ni. It is concluded that the contamination moves into the silicon by diffusion to vacancies created by the Ar+ ions. For 1 keV Ar+ ions the contamination moves to a depth of 25 Å, comparable to the penetration depth of the ions. After etching a 170 Å thick layer, the catalytic effect of contamination is reduced to less than 5%. A simple model, which describes the measured effect of contamination very well, indicates that only 3% of the contamination is removed when a monolayer of silicon is etched away. Besides this catalytic effect there are indications that contamination can also lower the etch rate under certain conditions, because of the formation of silicides. From the measurements no conclusions could be drawn about the underlying mechanism of etch rate enhancement. © 1999 American Vacuum Society