期刊文献分布特征的分析

以1999-2003年生物技术学科期刊文献分布曲线为依据,利用知识密度梯度graduR(n)的概念,对知识场中文献分布特征进行分析。结果表明,在任何一个学科的知识场中,集中区文献分布呈间断性变化,离散区文献分布呈连续性变化,从而构成期刊文献分布的基本特征。基于此,指出期刊文献分布特征研究是对文献分布规律的进一步描述。     

What’s in a Name: Differential labelling of plant and animal photographs in two nationally syndicated elementary science textbook series

This study investigated plant and animal photographs in elementary science textbooks to discern whether there were disparities in the number of plant and animal photographs or in how those photographs were labelled. We examined the Life Science sections of two nationally syndicated (USA) textbook series. For each text, we identified the photographs with plant and/or animal content and evaluated them for two features: (1) the subject of the photograph, and (2) the specificity of the label (name) provided. We found that photographs with animal subjects were more numerous than those with plant subjects; they also represented a greater diversity of animals and had a higher instance of repetition than did plant photographs. We also found a significant naming disparity: animal photographs were three times more likely to be provided with a specific label (common name) than were plant photographs. Not only were plant photographs less likely to be provided with a specific name for the plant (e.g. orchid or dandelion), but also they were commonly identified only by the name for a plant part (such as flower or leaf) or life‐form (e.g. tree or shrub). To address the disparity revealed by this study, and to encourage student interest in and knowledge about plants, we recommend that educators go beyond textbooks to expose students to a diversity of named plants, and present plants as distinct organisms rather than as a collection of parts.     

Defining Dispositions: Wading Through Murky Waters

Abstract

Efforts to professionalize teaching have coincided with a shift in teacher education programs. Recent requirements of accrediting bodies have resulted in initiatives to assess dispositions in addition to knowledge and skills. However, for such assessment to maintain construct validity, it is imperative first to develop some common understandings about the nature of dispositions and then to explore how teacher education should be addressing them. This paper explores dispositions from both a conceptual and a practical perspective. Dispositions are described as a point of convergence, representing a filter through which thinking and behaviors related to teaching are framed, and a point of inception, from which knowledge and behaviors emanate. This dispositional filter encompasses the teacher s awareness, inclination, and ability to reflect. Teacher education programs can foster dispositions by helping teacher candidates engage in self‐exploration of their personal theories and identify their own values and assumptions related to teaching.     

Does Instructor Type Matter? Undergraduate Student Perception of Graduate Teaching Assistants and Professors

Graduate teaching assistants (GTAs) are used extensively as instructors in higher education, yet their status and authority as teachers may be unclear to undergraduates, to administrators, and even to the GTAs themselves. This study explored undergraduate perception of classroom instruction by GTAs and professors to identify factors unique to each type of instructor versus the type of classes they teach. Data collection was via an online survey composed of subscales from two validated instruments, as well as one open-ended question asking students to compare the same class taught by a professor versus a GTA. Quantitative and qualitative results indicated that some student instructional perceptions are specific to instructor type, and not class type. For example, regardless of type of class, professors are perceived as being confident, in control, organized, experienced, knowledgeable, distant, formal, strict, hard, boring, and respected. Conversely, GTAs are perceived as uncertain, hesitant, nervous, relaxed, laid-back, engaging, interactive, relatable, understanding, and able to personalize teaching. Overall, undergraduates seem to perceive professors as having more knowledge and authority over the curriculum, but enjoy the instructional style of GTAs. The results of this study will be used to make recommendations for GTA professional development programs.     

Layers and links: Learning to juggle ‘one more thing’ in the classroom

This paper presents a model—hypertextual function—to consider teachers’ thinking, practice, and development in the use of technology. Hypertextual function is a multi-dimensional model linking a teacher's knowledge about students (familiarity) and technology (facility), with a teacher's teaching practice of integrating technology with content (transparency) and across disciplines and experiences (connectivity), and a teacher's sense of support (collegiality). Additionally, a teacher's context affects each of these. Such a model is important as technology becomes more pervasive and integrating technology into classrooms adds another layer of complexity to teaching. Case studies and graphic representations of the proposed model are presented.     

Instructional Experiences of Graduate Assistants Implementing Explicit and Reflective Introductory Biology Laboratories

Science education reform documents identify nature of science (NOS) as a critical component of scientific literacy and call for universities, colleges, and K-12 schools to explicitly integrate NOS learning into science curricula. In response to these calls, this study investigated the classroom practices of nine graduate assistants (GAs) who taught expository and inquiry laboratories that implemented an explicit and reflective (ER) pedagogy to teach NOS. The purpose of this qualitative study was to better understand the experiences that enabled or inhibited GA implementation of an ER strategy in a college setting. The findings revealed that achieving quality implementation in this setting was very difficult. Factors such as GAs' ability to foster meaningful classroom discussions, laboratory logistics (e.g. lack of time and supplies), and the value undergraduates and GAs saw in learning about NOS were identified by GAs and observed by the researchers as barriers to the technique maximizing its potential. Thus, for meaningful infusion of NOS into science curricula, pedagogical support for GAs to manage meaningful classroom discussions in support of NOS or other complex topics is recommended for an ER approach to NOS learning to be successful in college settings.     

Conceptualizing dispositions: intellectual,cultural, and moral domains of teaching

In this conceptual paper, we provide a heuristic that organizes dispositions in a manner that is useful for prospective teachers and teacher educators. The heuristic is organized around three domains of dispositions – intellectual, cultural, and moral. We use a small sample of teacher candidate journal entries to ground the discussion of each disposition domain. Our goal is to explore how teacher candidates are inclined to think through issues of content and pedagogy, the cultural backgrounds of their students, and the values driving their moral reasoning. A significant part of this exploration includes examining teacher candidate assumptions. We offer recommendations for how teacher education programs can provide opportunities for prospective teachers to consider their dispositions and to identify how their dispositions influence teaching decisions.