Dynamic dictionary updating     

Robert G. Crawford 《Information processing & management》1977,13(4):235-245

A method for updating the dictionary in a dynamic information retrieval system is presented. It is shown that as a collection changes through addition and deletion of documents, the appropriate set of index terms may be determined without complete periodic regeneration of the dictionary. Results are presented for experiments involving a complete change in collection membership, with the dynamic dictionary updating methods shown to be effective.  相似文献   

The computation of discrimination values     

Robert G. Crawford 《Information processing & management》1975,11(8-12)

Results have been reported showing the usefulness of discrimination value in automatic construction of dictionaries for information retrieval. While discrimination value is defined in the literature, no specific explanation of its computation is given. In this paper the computation of discrimination value is discussed, a relatively efficient algorithm is presented and an example is given.  相似文献   

Species-specific defense reactions in escape-from-fear situations     

Mary Crawford  Fred Masterson  Diane Wilson 《Learning & behavior》1977,5(1):63-72

Five experiments are reported in which rats were given CS-shock pairings and then permitted, in the absence of shock, to perform a hurdle-jump response that led to CS offset. In Experiment 1–4, the animals failed to learn the required response. Although several procedural variations were employed, the experimental groups continued to perform no better than backward-conditioned controls. In Experiment 5, some animals were punished for remaining immobile during a single trial at the start of hurdle-jump training. These animals performed significantly better than nonpunished controls and better than any group in Experiments 1–4. The results support the idea that the major role of the CS in escape-from-fear situations is to activate an innate motivational system which chooses between the species-specific defense reactions of freezing and fleeing.  相似文献   

Ethics and openness     

Eames M  Crawford D 《New scientist (1971)》1995,146(1979):54

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Exploring the Meaning and Paths of Advocacy for Undocumented Students’ Access to Education     

Emily R. Crawford 《Journal of Latinos & Education》2016,15(3):197-213

There is widespread national debate over how to address and advocate for undocumented immigrants in the United States. Education is key to the economic, occupational, and social mobility of young unauthorized immigrants, but policies and practices can hinder or open their access to education. Educators pursue a range of activities to support undocumented students in school. This article identifies the conceptualizations, strategies, and thought processes of educators who advocate for undocumented students. The results reveal that advocates’ backgrounds, resources, goals, identity, and the communities in which they advocate influence their perceptions and practices of advocacy.  相似文献   

Addressing 21st-century crises through children’s literature: picturebooks as partners for teacher educators     

Patricia A. Crawford  Sherron Killingsworth Roberts  Vicky Zygouris-Coe 《Journal of Early Childhood Teacher Education》2019,40(1):44-56

ABSTRACT

Teacher educators might consider using high-quality picturebooks as partners to help teacher candidates understand and navigate today’s painful world realities. From a critical perspective, these books also have the potential to reflect and shape empathy and action in regard to these difficult situations. This piece includes a rationale for using picturebooks to address human crises, findings related to a study of 21st-century representations of crises in picturebooks, and implications for sharing these books as pedagogical partners to engage with teacher candidates. To this end, we conducted a content analysis of recent 21st-century fictional picturebooks depicting human crises. Topics related to refugee status, poverty, homelessness, and hunger were analyzed to reveal common themes across these books related to persistence, courage, caring, and hope. Teacher educators who are eager to address 21st-century disasters, many of which are presented in sensitive and accessible ways in recent touchstone picturebooks, can find a ready and capable partner in these powerful picturebooks to help readers understand and navigate these human crises.  相似文献   

Research productivity and academics’ conceptions of research     

Angela Brew  David Boud  Sang Un Namgung  Lisa Lucas  Karin Crawford 《Higher Education》2016,71(5):681-697

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Engineering education on the ‘fuzzy’ front end: a high-technology entrepreneurship model     

G. P. Crawford  D. J. Broer 《European Journal of Engineering Education》2006,31(2):145-153

We have developed a university entrepreneurship program, culminating in a prototype and business plan, with five objectives: (1) value for all academic participants’ (2) introduction to engineering issues for students; (3) refinement of engineering students’ ‘soft’ skills; (4) training for students in creating value out of embryonic ideas; and (5) a genuine entrepreneurship opportunity for students who wish to pursue a start-up company. The framework is disclosed in the context of three case studies. Furthermore, educational outcomes are derived and discussed based on participant evaluations and faculty reflection. Value creation is evaluated in terms of student performance in graduation exams, in external competitions, industrial interest, investment, intellectual property creation, and market intelligence. Finally, factors that add value to or redirect university research are discussed in the context to better serve society.  相似文献   

Multipoint Desktop Video Conferencing in Teacher Education: Preliminaries,problems and progress     

Lachlan Crawford  Leslie Sharpe  Hu Chun  S. Gopinathan  Moo Swee Ngoh  Angela Wong 《Asia-Pacific Journal of Teacher Education》2002,30(1):67-78

Members of this research team are investigating the use of multipoint desktop video conferencing (MDVC) technology in Singapore to enhance the National Institute of Education's schools practicum partnership model. The project builds on the Singapore ONE ATM island-wide network and the high-speed ADSL line access provided by Singtel Magix. This infrastructure provides state-of-the-art support for the White Pine CU-SeeMe Meeting Point server and client software that enables students on teaching practice to conference with each other and their university-based supervisors. A typical conference involves four of five students at different schools and one staff member at the National Institute of Education in Singapore. These conferences provide opportunities for professional sharing between staff and students without the limits of time and space which are traditional constraints on conventional teaching practice.  相似文献   

Embracing the essence of inquiry: New roles for science teachers     

Barbara A. Crawford 《科学教学研究杂志》2000,37(9):916-937

“This is the thing I really get excited about. There are some great ideas here, some really neat projects. Wanda and Joan are working on amphibian decline. Ann is interested in territorial behavior or some sort of feeding behavior in crawdads. That is a good one to study because crawdads are an important decomposer in the stream. We're looking at what kinds of criteria in a stream make it habitable for different kinds of organisms. And when you see those different combinations of organisms, what do they mean? How do you interpret them? I mean we're really getting into higher levels of thinking, because we're looking at different kinds of organisms and interpreting them in terms of stream health.” Jake, biology teacher, Northwestern High School. © 2000 John Wiley & Sons, Inc. J Res Sci Teach 37: 916–937, 2000  相似文献