Uma crítica das qualificações: Políticas, práticas e assuntos técnicos

In recent years there was been a raft of criticisms of the way that grades (or marks) are assigned to students. The purpose of this paper is to examine the strengths and weaknesses of grading systems and grading practices, drawing upon both historical and contemporary research and writing. Five questions are used to frame the review and organize the paper. They are: (1) Why do we grade students? (2) What do grades mean? (3) How reliable are students’ grades? (4) How valid are students’ grades? and (5) What are the consequences of grading students?  The results suggest that (1) The are several purposes for grading students; the way that grades are assigned and reported should be consistent with the specified purpose. (2) Grades mean different things to different people (including the teachers who assign them). (3) Grades on a single task (e.g., a test or project, a homework assignment) are quite unreliable, whereas cumulative grades (that is, those based on several data sources) are reasonably reliable. (4) The validity of grades on a single task is virtually impossible to determine; however, the evidence suggests that cumulative grades are reasonably valid. (5) Grades influence a variety of student affective characteristics (e.g., self-esteem). However, their influence is no greater, nor less than, a host of other school-related factors.En años recientes ha habido una racha de críticas a la manera como las calificaciones o grados se asignan a los estudiantes. El propósito de este artículo es examinar las fortalezas y las debilidades de los sistemas y las prácticas de calificación, con base en texto e investigaciones históricas y contemporáneas. Se aprovechan cinco preguntas para marcar los límites y organizar el texto. 1) Por qué calificamos a los estudiantes. 2) Qué significan las calificaciones. 3) Qué tan confiables son las calificaciones de los estudiantes. 4) Qué tan válidas son. y 5) Cuáles son las consecuencias de calificar a los estudiantes. Los resultados sugieren que: 1) Hay diferentes propósitos para calificar a los estudiantes; la manera como se asignan y se reportan debiera ser consistente con el propósito especifico. 2) Las calificaciones tienen diferentes significados para diferentes personas, (incluyendo a los profesores que las asignan). 3) Las calificaciones asignadas a una sola tarea (esto es una prueba, un proyecto, una tareas) son muy poco confiables, mientras que las calificaciones acumuladas (esto es las que se basan en diferentes fuentes) son razonablemente confiables. 4) La validez de las calificaciones asignadas a una sola tarea es casi imposible de determinar, en cambio la evidencia sugiere que las calificaciones acumuladas son razonablemente válidas. 5) Las calificaciones influyen sobre las características afectivas de los estudiantes (por ejemplo, la autoestima), sin embargo su influencia no es mayor ni menor que un montón de otros factores escolares relacionados.Nos últimos anos, tem havido uma série de críticas sobre como as notas ou notas são atribuídas aos alunos. O objetivo deste artigo é examinar os pontos fortes e fracos dos sistemas e práticas de qualificação, baseados em textos e pesquisas históricas e contemporâneas. Cinco perguntas são usadas para marcar os limites e organizar o texto. 1) Por que classificamos os alunos? 2) O que as qualificações significam 3) Quão confiáveis são as notas do aluno. 4) Qual a sua validade e 5) Quais são as consequências de qualificar os alunos? Os resultados sugerem que: 1) Existem diferentes propósitos para qualificar os alunos; a maneira como são designados e relatados deve ser consistente com o propósito específico. 2) As notas têm significados diferentes para pessoas diferentes (incluindo os professores que as designam). 3) As classificações atribuídas a uma única tarefa (isto é, um teste, um projeto, uma tarefa) são pouco confiáveis, enquanto as qualificações acumuladas (isto é, aquelas baseadas em fontes diferentes) são razoavelmente confiáveis. 4) A validade das avaliações atribuídas a uma única tarefa é quase impossível de determinar, enquanto as evidências sugerem que as qualificações acumuladas são razoavelmente válidas. 5) As notas influenciam as características afetivas dos alunos (por exemplo, autoestima), porém sua influência não é maior ou menor do que muitos outros fatores relacionados à escola

Questões-chave para pensamento e ação

In this summary article, six recommendations for the design, implementation, and interpretation of educational evaluations are presented and discussed. These recommendations are based on common “threads” that run through most, if not all, of the papers included in this special issue. The recommendations concern (1) the need for awareness of the political, societal, cultural, and economic factors affecting evaluation studies; (2) the importance of knowing and understanding the stakeholder groups; (3) the need to ensure that the purposes of the evaluation are explicit and clear; (4) the importance of allowing flexibility in the implementation of the evaluation when needed to account for issues that arise during the evaluation process; (5) the need to ensure that the data gathered as part of the evaluation process are of the highest technical quality possible; and the (6) importance of ensuring that the results of the evaluation are interpreted correctly and well understood by stakeholders and decision makers.En este capítulo final se ofrecen y discuten seis recomendaciones para diseñar, implementar e interpretar evaluaciones educativas.  Estas recomendaciones se basan en las líneas comunes que corren a lo largo de la mayoría, si no es que de todos, los artículos incluidos en este número especial. 1) La necesidad de tener conciencia de los factores políticos, sociales, culturales y económicos que afectan a los estudios de evaluación: 2) la importancia de conocer y hacer explícitos a los actores involucrados; 3) la necesidad de asegurar que los propósitos de la evaluación sean explícitos y claros; 4) la importancia de permitir flexibilidad en la implementación de la evaluación cuando sea necesario dar cuenta de los tópicos de discusión que surjan durante el proceso de evaluación; 6) la Importancia de asegurar que los resultados de la evaluación sean interpretados correctamente y sean debidamente entendidos por los actores participantes y los tomadores de decisiones.Este capítulo final oferece e discute seis recomendações para projetar, implementar e interpretar avaliações educacionais. Estas recomendações são baseadas em linhas comuns que percorrem a maioria, se não todos, os artigos desta edição especial. 1) A necessidade de estar ciente dos fatores políticos, sociais, culturais e económicos que afectam os estudos de avaliação: 2) a importância de conhecer e explicitar os atores envolvidos; 3) a necessidade de garantir que os objetivos da avaliação sejam explícitos e claros; 4) a importância de permitir flexibilidade na implementação da avaliação, quando necessário para dar conta dos tópicos de discussão que surgem durante o processo de avaliação; 6) a importância de assegurar que os resultados da avaliação são interpretados corretamente e estão devidamente compreendido pelos atores participantes e decisores

Introdução à dossiê especial: Perspectivas históricas e contemporâneas sobre avaliação educacional

Most special issues on evaluation focus on one form or type of evaluation (e.g., program evaluation, personnel evaluation, and, increasingly, educational system evaluation. This special issue is unique in that there are papers on system evaluation, program evaluation, teacher evaluation, and student evaluation. Some papers are primarily conceptual, others are empirical, and still others are a little of each. Some papers are more historical, some contemporary, and some a little of each. The authors represent four countries: Canada, Mexico, South Africa, and the United States, providing an international perspective on key issues. The final paper contains six recommendations concerning the future of educational evaluation based on an analysis of commonalities across the papers.La mayoría de los números especiales sobre evaluación se centra en una forma o tipo de evaluación (por ejemplo, evaluación del programa, evaluación del personal y, cada vez más, evaluación de los sistemas educativos. Esta edición especial es única porque hay artículos sobre evaluación de los sistemas, evaluación de programas, evaluación, y evaluación de los alumnos Algunos trabajos son primariamente conceptuales, otros son empíricos, y otros todavía son un poco de cada uno. Algunos artículos son más históricos, algunos contemporáneos, y algunos un poco de cada uno. los autores representan cuatro países: Canadá, México, Sudáfrica y Estados Unidos, proporcionando una perspectiva internacional sobre cuestiones clave. El informe final contiene seis recomendaciones sobre el futuro de la evaluación educativa sobre la base de un análisis de similitudes entre los artículos.A maioria das dossiês especiais sobre avaliação se concentra em uma forma ou tipo de avaliação (por exemplo, avaliação de programa, avaliação de pessoal e, cada vez mais, avaliação de sistemas educacionais. Essa edição especial é única porque há artigos sobre avaliação de sistemas, avaliação de programas, avaliação, e avaliação dos alunos Alguns trabalhos são primariamente conceituais, outros são empíricos, e outros ainda são um pouco de cada um.Alguns artigos são mais históricos, alguns contemporâneos, e alguns um pouco de cada.Estes autores representam quatro países: Canadá, México, África do Sul, e Estados Unidos, proporcionando uma perspectiva internacional sobre questões-chave O relatório final contém seis recomendações sobre o futuro da avaliação educacional com base em uma análise de semelhanças entre os artigos

Correlation of radiographic and MRI parameters to morphological and biochemical assessment of intervertebral disc degeneration

Degenerative disc disease (DDD) is a common finding in MRI scans and X-rays. However, their correlation to morphological and biochemical changes is not well established. In this study, radiological and MRI parameters of DDD were assessed and compared with morphological and biochemical findings of disc degeneration. Thirty-nine human lumbar discs (L1-S1), age 19-86years, were harvested from eight cadavers. Within 48h postmortem, MRIs in various spin-echo sequences and biplanar radiographs of intact spines were obtained. Individual discs with endplates were then sectioned in the mid-sagittal plane and graded according to the morphological appearance. Samples from the nucleus of each disc were harvested for biochemical analysis including water and proteoglycan contents. On MRIs, T2-signal intensity, Modic changes, disc extension beyond the interspace (DEBIT), nucleus pulposus shape, annular tears, osteophytes and endplate integrity were graded. On radiographs, an independent observer classified the parameters disc height, endplate sclerosis, osteophytes, Schmorl's nodes, intradiscal calcifications and endplate shape. General linear-regression models were used for statistical analysis. Backward elimination with a 10% significance cut-off level was used to identify the most significant parameters, which then were summed to create composite scores for radiography, MRI and the combination of both methods. The grading was performed by three observers, and a reliability analysis using Cronbach's alpha model was used to control interobserver agreement. The three radiographic parameters height-loss, osteophytes and intradiscal calcifications correlated significantly with the morphological degree of degeneration (p<0.001, R2=642). Significant differences of even one morphological grade could also be differentiated in the composite radiological score (p<0.05), except at the extremes between grades 1 and 2 and grades 4 and 5. All MRI parameters correlated significantly with the morphological grade (p<0.05); however Modic changes, T2-intensity and osteophytes accounted for 83% of the variation in the data. T2-signal intensity correlated significantly with H2O and proteoglycan content (p<0.001), and was best for detecting highly degenerated discs. Regression showed that the combined score was better correlated with the morphological grade (p<0.001, R2 =775) than either the composite radiographic (p<0.001, R2 =642) or composite MRI (p<0.001, R2 =696) alone. Based on the combined score, a backwards elimination of the regression was performed, in which the parameters Modic changes, and T2-intensity loss (MRI) as well as calcifications (X-ray) accounted for 87% of the variability. The interobserver validation showed a high correlation for all three scores (Cronbach's alpha values ranging from 0.95 to 0.97). Conclusion: selective imaging parameters and a newly created scoring scheme were found to correlate with disc degeneration as determined in a morphological manner. Surprisingly, radiographic parameters were able to distinguish different stages of degeneration, whereas MRI could only detect advanced stages of disc degeneration. We conclude that X-rays may remain a cost-effective, non-invasive in vivo-grading method to detect early disc degeneration, and, combined with MRI, correlate best with morphological and biochemical assessment of disc degeneratio

Estabilidade do desempenho e eficácia do ensino: Implicações para as políticas de avaliação de professores

The last five to ten years has seen a renewed interest in the stability of teacher behavior and effectiveness. Data on teacher performance and teacher effectiveness are being used increasingly as the basis for decisions about continued employment, tenure and promotion, and financial bonuses. The purpose of this study is to explore the stability of both teacher performance and effectiveness by determining the extent to which performances and effectiveness of individual teachers fluctuate over time. The sample consisted of 132 teachers for whom both observational and state standardized test data were available for five consecutive years. Neither teacher performance nor effectiveness were highly stable over multiple years of the study. The observed relationship between teacher performance and teacher effectiveness was reasonably stable over time, but the magnitude of the relationship was quite small. Teacher performance was also likely to be inflated in low performing schools. We also discuss when different observed patterns may be acceptable based on the purpose for which the data are used.En los últimos cinco a diez años ha visto un renovado interés en la estabilidad de la conducta y la efectividad de los maestros. Los datos sobre el desempeño de los docentes y la eficacia docente se están utilizando cada vez más como la base para las decisiones sobre el mantenimiento del empleo, la tenencia y la promoción, y los bonos financieros. El propósito de este estudio es explorar la estabilidad de rendimiento y eficacia de los docentes analizando en que medida las actuaciones y la eficacia de los profesores individuales fluctúan con el tiempo. La muestra estuvo constituida estaban disponibles datos tanto observacionales y de pruebas estandarizadas durante cinco años consecutivos. Ni el desempeño docente ni la eficacia era muy estable a lo largo de varios años de estudio. La relación observada entre el desempeño de los docentes y la efectividad del maestro era razonablemente estable en el tiempo, pero la magnitud de la relación era bastante pequeña. Es probable que el desempeño de los docentes también se halla incrementado en escuelas de bajo rendimiento. También discutimos en que medida los diferentes patrones observados pueden ser aceptables como una base confiable para los fines propuestos por esas políticas. Nos últimos cinco a dez anos tem visto um renovado interesse na estabilidade do comportamento e da eficácia dos professores. Os dados sobre o desempenho e eficácia dos professores são cada vez mais usados como base para a toma de decisões sobre emprego retenção, posse e promoção, e incentivos. O objetivo deste estudo é explorar a estabilidade do desempenho e eficácia de professores analisando em que medida as ações e efetividade dos professores muda ao longo do tempo. A amostra foi composta por dados de 132 professores de exames e observações obtidos por cinco anos consecutivos. Nem o desempenho e a eficácia dos professores foram muito estáveis ao longo dos vários anos de estudo. A relação observada entre o desempenho do professor e eficácia do professor era razoavelmente estável ao longo do tempo, mas a magnitude da relação foi muito pequena. Desempenho dos professores também parece aumentar em escolas de baixo desempenho. Discutimos, também, em que medida os diferentes padrões observados podem ser aceitáveis para os objetivos das politicas.

Program evaluation : large-scale and small-scale studies

It is increasingly incumbent upon ministries of education to build evaluation into new programs – especially those programs where substantial amounts of money are being spent. Each new program will usually be accompanied by questions about the impact and effectiveness of the program. For example, ministries may direct increased resources to classrooms and schools. Question: “Have these resources gone where desired and have the increased resources had an effect on student achievement?” Or, a new curriculum may have been introduced. Question: “How was the curriculum introduced and what problems occurred with its implementation?” Or, a new teacher in-service program may have been developed. Question: “Did the teachers learn what they were meant to learn? And, if so, did what the teachers learn have an effect on what students learned in terms of achievement, attitudes, and/or behaviour?” These are some examples for the case of general school education, but the same is true for new programs in pre-schools, in schools for the handicapped, in vocational education, and so on. All education programs need to include an evaluation component if their success is to be determined, and if weaknesses in the programs are to be identified and corrected. When introducing new education programs it is not easy to assess whether they have had an effect on student learning. The kind of research design needed to get at the true cause of changes in student learning will vary according to the type of learning specified in the program goals. At the same time, however, there are some similarities in terms of sound and defensible evaluation designs. For example, it is always important that some measure of student learning be made at the beginning of a program. Education programs cannot be said to be effective if there are no measurable improvements in student learning over time. Similarly, some comparison group, or groups, of teachers and students should be included in the study. If there are measurable changes in student learning over time, but the magnitude of the changes is not different from changes that occur in non-program students, then the program cannot be said to be effective. This booklet is about small-scale and large-scale program evaluation studies. In many cases, both small- and large-scale studies are needed within any one evaluation project. In this booklet the authors argue that there is a need for both kinds of studies – provided that they are conducted according to scientific standards

The effect of thermophoresis on the discharge parameters in complex plasma experiments

Thermophoresis is a tool often applied in complex plasma experiments. One of the usual stated benefits over other experimental tools is that changes induced by thermophoresis neither directly depend on, nor directly influence, the plasma parameters. From electronic data, plasma emission profiles in the sheath, and Langmuir probe data in the plasma bulk, we conclude that this assumption does not hold. An important effect on the levitation of dust particles in argon plasma is observed as well. The reason behind the changes in plasma parameters seems to be the change in neutral atom density accompanying the increased gas temperature while running at constant pressure.Comment: 14 pages, 12 figure

Experimental and computational characterization of a modified GEC cell for dusty plasma experiments

A self-consistent fluid model developed for simulations of micro- gravity dusty plasma experiments has for the first time been used to model asymmetric dusty plasma experiments in a modified GEC reference cell with gravity. The numerical results are directly compared with experimental data and the experimentally determined dependence of global discharge parameters on the applied driving potential and neutral gas pressure is found to be well matched by the model. The local profiles important for dust particle transport are studied and compared with experimentally determined profiles. The radial forces in the midplane are presented for the different discharge settings. The differences between the results obtained in the modified GEC cell and the results first reported for the original GEC reference cell are pointed out

Predicating from an early age: edusemiotics and the potential of children’s preconceptions

This paper aims to explain how semiotics and constructivism can collaborate in an educational epistemology by developing a joint approach to prescientific conceptions. Empirical data and findings of constructivist research are interpreted in the light of Peirce’s semiotics. Peirce’s semiotics is an anti-psychologistic logic (CP 2.252; CP 4.551; W 8:15; Pietarinen in Signs of logic, Springer, Dordrecht, 2006; Stjernfelt in Diagrammatology. An investigation on the borderlines of phenomenology, ontology and semiotics, Springer, Dordrecht, 2007) and relational logic. Constructivism was traditionally developed within psychology and sociology and, therefore, some incompatibilities can be expected between these two schools. While acknowledging the differences, we explain that constructivism and semiotics share the assumption of realism that knowledge can only be developed upon knowledge and, therefore, an epistemological collaboration is possible. The semiotic analysis performed confirms the constructivist results and provides a further insight into the teacher-student relation. Like the constructivist approach, Peirce’s doctrine of agapism infers that the personal dimension of teaching must not be ignored. Thus, we argue for the importance of genuine sympathy in teaching attitudes. More broadly, the article also contributes to the development of postmodern humanities. At the end of the modern age, the humanities are passing through a critical period of transformation. There is a growing interest in semiotics and semiotic philosophy in many areas of the humanities. Such a case, on which we draw, is the development of a theoretical semiotic approach to education, namely edusemiotics (Stables and Semetsky, Pedagogy and edusemiotics: theoretical challenge/practical opportunities, Sense Publishers, Rotterdam, 2015)