Pragmatic meta analytic studies: learning the lessons from naturalistic evaluations of multiple cases

This paper explores the concept of pragmatic meta‐analytic studies in eLearning. Much educational technology literature focuses on developers and teachers describing and reflecting on their experiences. Few connections are made between these experiential ‘stories’. The data set is fragmented and offers few generalisable lessons. The field needs guidelines about what can be learnt from such single‐case reports. The pragmatic meta‐analytic studies described in this paper have two common aspects: (1) the cases are related in some way, and (2) the data are authentic, that is, the evaluations have followed a naturalistic approach. We suggest that examining a number of such cases is best done by a mixed‐methods approach with an emphasis on qualitative strategies. In the paper, we overview 63 eLearning cases. Three main meta‐analytic strategies were used: (1) meta‐analysis of the perception of usefulness across all cases, (2) meta‐analysis of recorded benefits and challenges across all cases, and (3) meta‐analysis of smaller groups of cases where the learning design and/or use of technology are similar. This study indicated that in Hong Kong the basic and non‐interactive eLearning strategies are often valued by students, while their perceptions of interactive strategies that are potentially more beneficial fluctuate. One possible explanation relates to the level of risk that teachers and students are willing to take in venturing into more innovative teaching and learning strategies

Invariant surface area functionals and singular Yamabe problem in 3-dimensional CR geometry

We express two CR invariant surface area elements in terms of quantities in pseudohermitian geometry. We deduce the Euler-Lagrange equations of the associated energy functionals. Many solutions are given and discussed. In relation to the singular CR Yamabe problem, we show that one of the energy functionals appears as the coefficient (up to a constant multiple) of the log term in the associated volume renormalization.Comment: 50 page

On the Sobolev quotient of three-dimensional CR manifolds

We exhibit examples of compact three-dimensional CR manifolds of positive Webster class, {\em Rossi spheres}, for which the pseudo-hermitian mass as defined in \cite{CMY17} is negative, and for which the infimum of the CR-Sobolev quotient is not attained. To our knowledge, this is the first geometric context on smooth closed manifolds where this phenomenon arises, in striking contrast to the Riemannian case.Comment: 36 pages, 2 figure

County-Specific Net Migration by Five-Year Age Groups, Hispanic Origin, Race and Sex 2000-2010

This report documents the methodology used to prepare county-level, net migration estimates by five-year age cohorts and sex, and by race and Hispanic origin, for the intercensal period from 2000 to 2010. The estimates were prepared using a vital statistics version of the forward cohort residual method (Siegel and Hamilton 1952) following the techniques used to prepare the 1990 to 2000 net migration estimates (Voss, McNiven, Johnson, Hammer, and Fuguitt 2004) as described in detail below. These numbers (and the net migration rates derivable from them) extend the set of decennial estimates of net migration that have been produced following each decennial census beginning with 1960 (net migration for the 1950s: Bowles and Tarver, 1965; 1960s: Bowles, Beale and Lee, 1975; 1970s: White, Mueser and Tierney, 1987; 1980s: Fuguitt, Beale, and Voss 2010; and 1990s: Voss, McNiven, Hammer, Johnson and Fuguitt, 2004)

Epiphyllous liverworts on rosette leaves of Ardisia species (Myrsinaceae) in China

Four species of Ardisia (Myrsinaceae, Magnoliopsida) with rosette or low-lying leaves in China (including Hong Kong) have been found to be the hosts for 12 species of epiphyllous liverworts which belong to 4 families and 9 genera. However, no obvious species-specific hostepiphyte relationship could be recognized