Query Expansion with Long-Span Collocates   总被引：1，自引：0，他引：1  

Olga Vechtomova  Stephen Robertson  Susan Jones 《Information Retrieval》2003,6(2):251-273

The paper presents two novel approaches to query expansion with long-span collocates—words, significantly co-occurring in topic-size windows with query terms. In the first approach—global collocation analysis—collocates of query terms are extracted from the entire collection, in the second—local collocation analysis—from a subset of retrieved documents. The significance of association between collocates was estimated using modified Mutual Information and Z score. The techniques were tested using the Okapi IR system. The effect of different parameters on performance was evaluated: window size, number of expansion terms, measures of collocation significance and types of expansion terms. We present performance results of these techniques and provide comparison with related approaches.  相似文献   

Developmental changes and socioeconomic differences in mother-infant picturebook reading     

Olga Alicia Peralta de Mendoza 《European Journal of Psychology of Education - EJPE》1995,10(3):261-272

Picturebook reading is a common form of interaction between parents and young children. This study examined developmental changes and socioeconomic differences in picturebook interactions of motherinfant Argentine dyads. 21 middle and 18 low SES mothers with their 12 to 24 months-old infants interacting with two different books, were observed. It was found that mothers of both SES groups adjusted the level of their demands not only to the task requirements (books) but also to the age of the infant. However, it was also found that the style of the interaction was different depending on the SES of the mother-infant pair. A more demanding and elaborated maternal language along with a linguistically more competent child were found in the middle SES group.  相似文献   

Learning activities as enactments of learning affordances in MUVEs: A review-based classification     

Olga Mantziou  Nikiforos M. Papachristos  Tassos A. Mikropoulos 《Education and Information Technologies》2018,23(4):1737-1765

Three Dimensional Multi-User Virtual Environments (MUVEs) are promising tools in education because of the unique affordances they offer. These learning affordances imply certain actions that in turn can lead to corresponding learning activities. There seems to be a lack of reports on which of the affordances of MUVEs for learning and teaching are used and how they are enacted by relevantly designed learning activities. This study investigates the learning activities conducted in Second Life, the most popular and widely used among the "sandbox" type MUVE platforms, as reported in 205 empirical studies, by associating them with the learning affordances they enact. As necessary step towards this goal, the study proposes a new classification of learning affordances of MUVEs and a new concrete set of learning activities based on the literature review. Learning affordances include free navigation, creation, modeling and simulation, multichannel communication, collaboration and cooperation and content presentation and/or delivery. By using the open, axial and selective coding offered by the grounded method, the learning activities that emerged from the exhaustive empirical review, are well associated with the proposed six learning affordances, validating in return the functionality of the proposed set of learning affordances. The five more general learning activities, resulting from the selective coding, are content creation, content exploration and interaction with content, social interaction, gaming, participation in representations of real life events and situations. Further research on other MUVEs is needed to establish this framework.  相似文献   

Missing the Forest for the Trees     

Olga Maia Amaral  Leslie Garrison 《Journal of Science Education and Technology》2007,16(2):155-169

This case study examines the alignment between the Intended Curriculum, Implemented Curriculum and Achieved Curriculum of a fourth grade inquiry based unit, Food Chains and Webs. Specifically addressed are how the curriculum was modified to meet state standards, how teachers were trained, and how assessment of curricular implementation was aligned with student performance. Particular focus was placed on measuring how well students connect the findings of inquiry based lessons to larger scientific principles. Implications of this study suggest modifications necessary for effective teacher professional development and classroom practice.  相似文献   

Education Inequality In Slovakia: The Effects Of Early Selection     

Olga Zelmanova  Paulina Korsnakova  Lucia Tramonte  J. Douglas Willms 《Prospects》2006,36(4):529-538

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Graphemes as Motor Units in the Acquisition of Writing Skills     

Sonia Kandel  Olga Soler  Sylviane Valdois  Céline Gros 《Reading and writing》2006,19(3):313-337

This study examined whether the graphemic structure of words modulates the timing of handwriting production during the acquisition of writing skills. This is particularly important during the acquisition period because phonological recoding skills are determinant in the elaboration of orthographic representations. First graders wrote seven-letter bi-syllabic words on a digitiser. We measured movement duration and fluency and evaluated reading performance. In Experiment 1, the words varied in number of graphemes and grapheme structure. In Experiment 2, the words varied in graphemic structure but the number of graphemes was held constant. The results revealed that the children wrote the first syllable of the words grapheme-by-grapheme, irrespective of the number of letters that composed them. They prepared the movement to produce the first grapheme before starting to write. The following graphemes were processed on-line. They then prepared the movement to write the second syllable. The progressive decrease of duration and dysfluency values towards the end of the word indicates that the children prepared the entire syllable in advance. Movement time and dysfluency measures presented very similar patterns in the two experiments. Furthermore, there was a significant correlation between reading performance and handwriting measures. The grapheme and syllable structure of the words therefore modulates the timing of motor production during handwriting acquisition. Once the children have learned the phonological recoding rules, they apply them systematically, irrespectively of the size of the graphemes they have to write.  相似文献   

A review of reliability procedures for measuring observer agreement     

Olga Towstopiat 《Contemporary educational psychology》1984,9(4):333-352

The present article reviews the procedures that have been developed for measuring the reliability of human observers' judgments when making direct observations of behavior. Measures such as the percentage of agreement, Cohen's kappa, and phi have been used to measure observer agreement; however, these coefficients have serious limitations. In addition to specifying the deficiencies that exist with these excessively used reliability measures, the present article discusses recently developed univariate and multivariate agreement measures that are based on quasi-equiprobability and quasi-independence models and estimates. Improvements in precision are provided by such models and estimates since they (1) yield a probability based coefficient of agreement with a directly interpretable meaning, (2) correct for the proportion of “chance” agreement, and (3) allow the partitioning of the agreement and disagreement estimates within the models.  相似文献   

Portfolios and assessment in teacher education in Norway: a theory‐based discussion of different models in two sites     

Olga Dysthe 《Assessment & Evaluation in Higher Education》2004,29(2):239-258

Two teacher institutions in Norway involved in a new ICT‐supported portfolio project provide data for our study. In this paper we present a model of analysis for portfolio processes based on sociocultural perspectives of learning and assessment and describe and discuss differences and similarities of the portfolio models in these institutions in relation to our model of analysis. We also highlight areas for improvement; among them the importance of building reflection, self‐assessment and feedback into portfolio assignments and processes in such a way that it becomes part of what is documented. This will strengthen the formative assessment aspect of portfolios. The summative assessment practices are strongly influenced by exam traditions in both institutions. Digital portfolios provide new learning opportunities that are not yet fully utilized. By way of conclusion we explore some critical aspects of portfolios in teacher education in light of Wenger's social theory of learning, focusing on the concepts participation, reification and identity formation.  相似文献   

Closing the gap on the map: Davydov’s contribution to current early algebra discourse in light of the 1960s Soviet debates over word-problem solving     

Freiman  Viktor  Fellus  Olga O. 《Educational Studies in Mathematics》2021,106(3):343-361

Recent scholarship around teaching elementary mathematics supports the learning of early algebra with 5- to 12-year olds. However, in spite of the recognition of the affordances of early algebra, issues about how to introduce it remain open. Within this context, Davydov’s work is often cited as a source of impressive demonstration of young learners’ capacity for algebraic thinking. This work requires further exploration in order to yield a clearer picture of a very particular teaching approach, which focuses on early abstractions and symbolic language. We argue that in order to fully understand how Davydov’s work contributes to current conversations and what Davydov was trying to do, we need to shed light on the context- and time-specific discourse of the 1960 Soviet educational reforms that made it possible for Davydov to develop his vision about algebraic thinking and to set in motion appropriate teaching approaches for young learners. In this paper, we look back to the Soviet debates that unfolded in Russia on the integration of early algebra in elementary school word-problem solving. Drawing on these debates and the results of Davydov’s school experiments, we lay out the developmental axes of capacity building. This can be done by emphasizing ascent from the abstract to the concrete using a variety of representational modeling tools to support the emergence of algebraic thinking while targeting particular habits of mind within carefully designed learning activities. We conclude with some insights about current arithmetic-algebra debates, and how these could be enriched and deepened by Davydov’s work, which yet remains open to future discussion and reflection.

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Pupils’ conceptions of force in inanimates and animates     

Olga Megalakaki 《European Journal of Psychology of Education - EJPE》2008,23(3):339-353

The objective of this work was to highlight the conceptions of force held by students aged 10–17 years old, in situations where animate and inanimate objects interact. In the proposed experimental situations, we varied parameters such as the motion and position of an object and the agent’s effort. We asked questions about both inanimate and animate objects. Results show that pupils are able to use a small number of conceptions coherently, but that these are influenced by the context. For inanimate objects, conceptions develop gradually. Initially, force is regarded as a property of objects related to their weight and/or motion/position. With age, however, pupils begin to regard it as a process of interaction. For animates, conceptions evolve much more slowly, insofar as all pupils consider force to be a human property related to the result that is obtained and/or the agent’s effort.  相似文献