title: (In)Stability of Test Scores

authors: Merchant, S

abstract: Both school and district administrators use the results of standardized, large-scale tests to inform decisions about the need for, or success of, educational programs and interventions. However, test results at the school level are subject to random fluctuations due to changes in cohort, test items, and other factors outside of the school’s control. This study examined year to year changes in school level results on standardized tests delivered in Ontario, Canada. G-theory analyses found that test scores are not stable enough for meaningful conclusions to be made based on year to year changes in school level results. For small and medium sized schools, years of data need to be collected before defensible decisions can be made about trends in test scores. The authors introduce a ‘bounce’ statistic that provides a simple, easy to interpret measure of test score stability.

text: (In)Stability of Test Scores Both school and district administrators use the results of standardized, large-scale tests to inform decisions about the need for, or success of, educational programs and interventions. However, test results at the school level are subject to random fluctuations due to changes in cohort, test items, and other factors outside of the school’s control. This study examined year to year changes in school level results on standardized tests delivered in Ontario, Canada. G-theory analyses found that test scores are not stable enough for meaningful conclusions to be made based on year to year changes in school level results. For small and medium sized schools, years of data need to be collected before defensible decisions can be made about trends in test scores. The authors introduce a ‘bounce’ statistic that provides a simple, easy to interpret measure of test score stability.

year: 2022-01-01

title: Population genetic structure of New Zealand's endemic corophiid amphipods: evidence for allopatric speciation

authors: Stevens, Mark I.

subjects: allozyme

abstract: Allozyme electrophoresis was used to examine population genetic structure at inter- and intraspecific levels for the New Zealand endemic corophiid amphipods, Paracorophium lucasi and P. excavatum. Individuals were collected from estuarine and freshwater habitats from North, South and Chatham Islands. Analyses of genetic structure among interspecific populations indicated clear allelic differentiation between the two Paracorophium species (Nei's genetic distance, D = 1.62), as well as considerable intraspecific substructuring (D = 0.15–0.65). These levels of divergence are similar to interspecific levels for other amphipods and it is proposed that at least two groups from the P. lucasi complex and three from the P. excavatum complex correspond to sibling species. In most cases allopatry can account for the differentiation among the putative sibling species. For populations that share a common coastline we found low levels of differentiation and little or no correlation with geographical distance, suggesting that gene flow is adequate to maintain homogeneous population genetic structure. By contrast, populations on separate coastlines (i.e. isolated by land) showed moderate levels of geographical differentiation indicating restricted gene flow. The juxtaposition of population genetic and biogeographical data for Paracorophium in conjunction with the geological record infers past histories of glacial extirpation, and possible isolating effects of sea-level and landmass changes that have occurred throughout the Plio-Pleistocene.

text: Population genetic structure of New Zealand's endemic corophiid amphipods: evidence for allopatric speciation Allozyme electrophoresis was used to examine population genetic structure at inter- and intraspecific levels for the New Zealand endemic corophiid amphipods, Paracorophium lucasi and P. excavatum. Individuals were collected from estuarine and freshwater habitats from North, South and Chatham Islands. Analyses of genetic structure among interspecific populations indicated clear allelic differentiation between the two Paracorophium species (Nei's genetic distance, D = 1.62), as well as considerable intraspecific substructuring (D = 0.15–0.65). These levels of divergence are similar to interspecific levels for other amphipods and it is proposed that at least two groups from the P. lucasi complex and three from the P. excavatum complex correspond to sibling species. In most cases allopatry can account for the differentiation among the putative sibling species. For populations that share a common coastline we found low levels of differentiation and little or no correlation with geographical distance, suggesting that gene flow is adequate to maintain homogeneous population genetic structure. By contrast, populations on separate coastlines (i.e. isolated by land) showed moderate levels of geographical differentiation indicating restricted gene flow. The juxtaposition of population genetic and biogeographical data for Paracorophium in conjunction with the geological record infers past histories of glacial extirpation, and possible isolating effects of sea-level and landmass changes that have occurred throughout the Plio-Pleistocene.

year: 2004

title: The enowning of thought and whakapapa: Heidegger's fourfold

authors: Mika, Carl Te Hira

subjects: Maori

abstract: Throughout colonization, Maori have been constantly urged to think of their terminology, and the objects it relates to, along constrained lines. In this practice, the self and other things are arguably restricted and impoverished. However, certain frequently used Maori terms – such as “whakapapa” and “whakaaro” – may be read alongside Heidegger’s “Ereignis,” revealing a completely other sense to them than their orthodox, respective translations of “genealogy” and “to think” allow. This kind of thinking in concert with an existential philosophy is an active process that allows for the “freeing up” of entities and a colonized group. With Heidegger’s assistance, the terms, and the original sources they refer to, reflect a kind of “Geviert”/Fourfold that ensures a continual strife and interplay between things in the world and self.

text: The enowning of thought and whakapapa: Heidegger's fourfold Throughout colonization, Maori have been constantly urged to think of their terminology, and the objects it relates to, along constrained lines. In this practice, the self and other things are arguably restricted and impoverished. However, certain frequently used Maori terms – such as “whakapapa” and “whakaaro” – may be read alongside Heidegger’s “Ereignis,” revealing a completely other sense to them than their orthodox, respective translations of “genealogy” and “to think” allow. This kind of thinking in concert with an existential philosophy is an active process that allows for the “freeing up” of entities and a colonized group. With Heidegger’s assistance, the terms, and the original sources they refer to, reflect a kind of “Geviert”/Fourfold that ensures a continual strife and interplay between things in the world and self.

year: 2014