▶ Eta squared and partial eta squared are measures of effect size. ▶ In the past, they have been confused in the research literature. ▶ Nowadays, partial eta squared is widely cited as a measure of ...effect size. ▶ The interpretation of both measures needs to be undertaken with care.
Eta squared measures the proportion of the total variance in a dependent variable that is associated with the membership of different groups defined by an independent variable. Partial eta squared is a similar measure in which the effects of other independent variables and interactions are partialled out. The development of these measures is described and their characteristics compared. In the past, the two measures have been confused in the research literature, partly because of a labelling error in the output produced by certain versions of the statistical package SPSS. Nowadays, partial eta squared is overwhelmingly cited as a measure of effect size in the educational research literature. Although there are good reasons for this, the interpretation of both measures needs to be undertaken with care. The paper concludes with a summary of the key characteristics of eta squared and partial eta squared.
Headwaters, the sources of all stream networks, provide habitats that are unique from other freshwater environments and are used by a specialised subset of aquatic species. The features of headwaters ...that provide special habitats include predator-free or competitor-free spaces; specific resources (particularly detrital based); and moderate variations in flows, temperature and discharge. Headwaters provide key habitats for all or some life stages for a large number of species across just about all freshwater phyla and divisions. Some features of headwaters, including isolation and small population sizes, have allowed for the evolutionary radiation of many groups of organisms within and beyond those habitats. As small and easily engineered physical spaces, headwaters are easily degraded by streambank development, ditching and even burial. Headwater streams are among the most sensitive of freshwater ecosystems due to their intimate linkage with their catchments and how easily they are impacted. As a unique ecosystem with many specialist species, headwater streams deserve better stewardship.
The reign of Augustus, the first of the Roman emperors, has been seen, both by contemporaries and over the centuries that have followed, as a pivotal moment in the history of Rome. The final stage in ...the move to monarchical government and the structures he put in place, which were to last largely unchanged for over two hundred years, ensured this; but Augustus himself remains an enigmatic figure.
A literature review published in 2008 outlined known relationships between gender, ethnicity, and academic attainment in UK higher education. In the period since this publication, many changes to the ...higher education sector have occurred, including raising tuition fees, an increased focus on widening participation, and an increasing interest in diversifying the curriculum. There is a need for an updated and expanded literature review to highlight whether the relationships between gender, ethnicity, and academic attainment remain the same one decade later. This article synthesises the current literature related to the impact of gender, social class, and ethnicity on higher education participation and academic attainment. We highlight the important role of intersectionality in understanding overarching trends. Altogether, this literature review shows that there are persisting inequalities in both participation and attainment based on gender, social class, and ethnicity. To conclude, we provide several suggestions for improving our understanding of these phenomena in the decades to come.
A Latin square is a matrix containing the same number of rows and columns. The cell entries are a sequence of symbols inserted in such a way that each symbol occurs only once in each row and only ...once in each column. Fisher (1925) proposed that Latin squares could be useful in experimental designs for controlling the effects of extraneous variables. He argued that a Latin square should be chosen at random from the set of possible Latin squares that would fit a research design and that the Latin-square design should be carried through into the data analysis. Psychological researchers have advanced our appreciation of Latin-square designs, but they have made only moderate use of them and have not heeded Fisher's prescriptions. Educational researchers have used them even less and are vulnerable to similar criticisms. Nevertheless, the judicious use of Latin-square designs is a powerful tool for experimental researchers.
•Fisher (1925) proposed that Latin squares could be useful in experimental design.•He argued that Latin squares should be chosen at random and used in data analysis.•Educational and psychological researchers have used Latin squares only rarely.•Those who have used Latin squares have often not heeded Fisher's prescriptions.•Nevertheless, the judicious use of Latin-square designs can be a powerful tool.
Tributary junctions in stream networks provide unique habitats within fluvial networks by contributing differently sized sediment and organic materials, providing temperature refuge, and other ...conditions distinct from the receiving stream. These same attributes at tributaries entering lakes (inflow streams) support special, within‐lake locations that are used by several organisms at some times of year, which we call lake deltas.
Here we consider the evidence of these lake deltas as a special environment in terms of their physical, chemical, and biological characteristics. There are several potential contributions from tributary streams, and much of the emphasis has been on resource subsidies to lakes, but other factors may also contribute to the uniqueness of lake deltas.
The degree to which these deltas provide productivity and biodiversity hotspots is not well known, but we present evidence in support of this assertion. We also offer suggestions for a suite of hypotheses that can be tested. These junctions may also provide an excellent model system for testing the consequences of resource subsidies (organic matter, invertebrates) to recipient communities from small to mid‐sized streams.
Consolidation of these ideas will allow testing for the uniqueness of these lake delta habitats and the mechanisms responsible, and perhaps promote greater efforts at protecting processes that sustain these areas in lakes.
The umbrella-species concept, which suggests that conservation strategies designed for one species may benefit co-occurring species, has been promoted as a framework for conservation planning. ...Nevertheless, there has been considerable variation in the outcome of empirical tests of this concept that has led researchers to question its value, so we used data from 15 published studies in a meta-analysis to evaluate whether conservation of putative umbrella species also conserves co-occurring species. We tested the effectiveness of putative umbrella species categorized by taxonomic group, taxonomic similarity to co-occurring species, body size, generality of resource use, and trophic level to evaluate criteria proposed to guide the selection of umbrella species. We compared species richness and number of individuals (by species and higher taxonomic group) between sites with and without putative umbrella species to test whether more co-occurring species were present in greater abundances when the area or resource needs of umbrella species were met. Species richness and abundance of co-occurring species were consistently higher in sites where umbrella species were present than where they were not and for conservation schemes with avian than with mammalian umbrella species. There were no differences in species richness or species abundance with resource generalist or specialist umbrella species or based on taxonomic similarity of umbrella and co-occurring species. Taxonomic group abundance was higher in across-taxonomic umbrella species schemes than when umbrella species were of the same taxon as co-occurring species. Co-occurring species had similar, or higher, species richness with small-bodied umbrella species relative to larger-bodied umbrella species. The only significant difference among umbrella species categorized by trophic level was that species richness was higher with omnivorous than it was with carnivorous avian umbrella species. Our results suggest there is merit to the umbrella-species concept for conservation, but they do not support the use of the criteria we used to identify umbrella species.
The understanding of inertial-scale dynamics in the heliosheath is not yet thorough. Magnetic field fluctuations across the inner heliosheath (IHS) and the local interstellar medium (LISM) are here ...considered to provide accurate and highly resolved statistics over different plasma conditions between 88 and 136 au. By using the unique in situ 48 s measurements from the Voyager Interstellar Mission, we investigate different fluctuation regimes at the magnetohydrodynamic (MHD) scales, down to the MHD-to-kinetic transition. We focus on a range of scales exceeding five frequency decades (5 × 10−8 < f < 10−2 Hz), which is unprecedented in literature analysis. A set of magnetic field data for eight intervals in the IHS, in both unipolar and sector regions, and four intervals in the LISM is used for the analysis. Results are set forth in terms of the power spectral density, spectral compressibility, structure functions, and intermittency of magnetic field increments. In the heliosheath, we identify the energy-injection regime displaying a ∼1/f energy decay, and the inertial-cascade regime. Here, the power spectrum is anisotropic and dominated by compressive modes, with intermittency that can reach kurtosis values of up to 10. In the interstellar medium the structure of turbulence is anisotropic as well, with transverse fluctuations clearly prevailing after 2015 May. Here, we show that intermittent features occur only at scales smaller than 10−6 Hz.
Recent research on student learning in higher education has identified clear associations between variations in students' perceptions of the academic environment and variations in their study ...behaviour. This study investigated a general theoretical model linking students' demographic characteristics, perceptions and study behaviour with measures of outcome, and in particular, compared three accounts of the causal relationship between perceptions and study behaviour. Data were obtained from 469 postgraduate students at six British business schools. Path analysis was used to assess the causal relationships among the students' age and gender, their scores on the Course Experience Questionnaire, their scores on the Revised Approaches to Studying Inventory and their ratings of general satisfaction with their programmes. This yielded evidence for the causal efficacy of most of the paths identified in the general theoretical model. In particular, as in the case of students taking more traditional academic subjects, there exists a bidirectional causal relationship between variations in students' perceptions of the academic environment and variations in their study behaviour.
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