Supporting problem solving with asynchronous online discussions: a social network analysis

Educational technology research and development - Asynchronous online discussions (AODs) are a central component of online courses and have been widely implemented in case-based instruction (CBI)....     

Tweet,and We Shall Find: Using Digital Methods to Locate Participants in Educational Hashtags

Although researchers have discovered a great deal about who uses Twitter for educational purposes, what they post about, when they post and why they participate, there has so far been little work to explore where participants in educational Twitter contexts are located. In this paper, we establish a methodological foundation that can support the exploration of geographical issues in educational Twitter research. We surveyed 46 participants in one educational Twitter hashtag, #michED, to determine where they lived; we then compared these responses to results from three digital methods for geolocating Twitter users (human coding, machine coding and GPS coding) to explore these methods’ affordances and constraints. Human coding of Twitter profiles allowed us to analyze more participants with higher levels of accuracy but also has disadvantages compared to other digital—and traditional—methods. We discuss the additional insights obtained through geolocating #michED participants as well as considerations for using geolocation and other digital methods in educational research.     

From evaluations to an equitable selection of merit-pay recipients and increments

In the absence of a viable salary-growth model, reasonable people generate arbitrary criteria with nebulous weighting factors for the decisions concerning initial salaries and subsequent increments. Generally, the resulting decisions yield lock-step, salary-growth patterns which include inequities, lack appropriate incentives, and are unsynchronized with cost-of-living increases. A model is described herein which includes the nature of the salary dependence on experience for various levels of performance of faculty members in a subset having the same level of education and the same marketability of their specialties. Application of the model to one subset provides objective procedures which yield, via successive approximations, initial salaries and subsequent increments with optimal equity. Similar application of the model to the several faculty subsets of an institution provides order and equitable order of magnitude in the decisions concerning all initial salaries and all subsequent increments. Consequences of such decision making include incentives to accept the risks of more comprehensive evaluations; rectification of lock-step, salary-growth patterns; and, optimally equitable rewards in consonance with the institution's mission and goals.     

俄罗斯Chukchi半岛新生代碱性岩的形成和演化：熔体和流体包裹体证据

Melt and fluid inclusions were studied in the minerals of Cenozoic olivine melanephelinites from the Chukehi Peninsula, Russia. The rock contain several generations of olivine phenocrysts varying in composition at mg=0.88 - 0.77. The phenocrysts bear fluid and melt inclusions recording various stages of melt crystallization in volcanic conduits and shallow magma chambers. Primary fluid inclusions are CO2-dominated with a density of up to 0.93 g/cm^3. All fluid inclusions are partially leaked, which is indicated by haloes of tiny fluid bubbles around large fluid inclusions in minerals. Melt inclusions contain various daughter crystals, which were completely resorbed in thermometric experiments at about 1230~C. Assuming that this temperature corresponds to the entrapment conditions of the CO2 fluid inclusions, the minimum pressure of the beginning of magma degassing is estimated as 800MPa. Variations in the compositions of homogenized silicate melt inclusions indicate that olivine was the earliest crystalline phase followed by clinopyroxene, nepheline and orthoclase. This sequence is in agreement with the mineralogy of the rocks. The melts are strongly enriched in incompatible trace elements and volatiles （in addition to CO2 , high C1, F, and S contents were detected）. There are some differences between the compositions of melts trapped in minerals from different samples. Variations in SiO2 , FeO, and incompatible element contents are probably related to melt generations at various levels in a homogeneous mantle reservoir.     

数字化图书馆和WWW站点及其页面的持续性

依据Web 页面和W eb 站点可以被搜集和分类, 文章探讨的主题是:WWW 构成图书馆。结论是:Web 不是数字化图书馆, 但是图书馆可以从Web 中选择搜集材料。Web 文献有两种变化形式。第一种变化形式是本文所谈论的“持续性”; 第二种变化形式是W eb 页面或Web 站点信息的变化。本文力求更进一步认识Web 页面和Web 站点的生存期, 生存期的变化会影响具有Web 信息的图书馆的完整性和有效性, 然而如果能够认识这些变化就可以进行控制和管理。