Trace and long-delay fear conditioning in the developing rat

In two experiments with rats, we examined the developmental emergence of conditioned freezing following trace and short-delay conditioning and also included a long-delay comparison group. In the short-delay and trace groups, a 10-sec conditioned stimulus (CS) was paired with shock; for the trace rats, a 10-sec trace interval followed CS termination. The long-delay groups received a 20-sec CS paired with shock, to equate for the longer interstimulus interval (ISI) in the trace group. Trace conditioning emerged later in development than did short-delay conditioning (see Moye & Rudy, 1987). Importantly, long-delay conditioning emerged in parallel with trace conditioning, at a similar time, and with similar strength. These findings suggest a role for the longer ISI, as opposed to the unfilled gap per se, in the late emergence of trace conditioning. The role of the hippocampus in trace conditioning and the possibility that young rats encode the temporal relationship between CSs and unconditioned stimuli are also considered.     

Dynamics of list-server discussion on genetically modified foods

Computer-mediated discussion lists, or list-servers, are popular tools in settings ranging from professional to personal to educational. A discussion list on genetically modified food (GMF) was created in September 2000 as part of the Forum on Genetically Modified Food developed by Science Controversies: Online Partnerships in Education (SCOPE), an educational project that uses computer resources to aid research and learning around unresolved scientific questions. The discussion list "GMF-Science" was actively supported from January 2001 to May 2002. The GMF-Science list welcomed anyone interested in discussing the controversies surrounding GMF. Here, we analyze the dynamics of the discussions and how the GMF-Science list may contribute to learning. Activity on the GMF-Science discussion list reflected some but not all the controversies that were appearing in more traditional publication formats, broached other topics not well represented in the published literature, and tended to leave undiscussed the more technical research developments.     

The nature of lead users and measurement of leading edge status

“Lead users” are defined as being at the leading edge of markets, and as having a high incentive to innovate. Empirical research has shown the value of lead user need and solution data to new product development processes. However, the nature of the lead user construct itself has not been studied to date. In this paper we fill this significant gap by proposing and evaluating a continuous analog to the lead user construct, which we call leading edge status (LES). We establish the validity and reliability of LES and examine the characteristics of users having high levels of this variable. We also offer a first exploration of how LES is related to traditional measures in diffusion theory such as dispositional innovativeness and time of adoption (TOA). We find a strong relationship and explain how users with high LES can offer a contribution to both predicting and accelerating early product adoption.     

Teachers' Professional Noticing

Teachers' instructional practice is pedagogically vulnerable when not anchored within detailed and comprehensive observation and understanding of students' immediate responses during instruction. Professional noticing ability, then, is central to, and integrated within, teachers' ability to provide instruction appropriately adapted to students' immediate needs. This article explicates a model of expert noticing for literacy instruction and relates this model to the characteristics of microadaptive teaching decisions. Characteristics, for example, that distinguish expert from less expert noticing during literacy instruction include detailed hypothesizing, breadth and depth of elaboration, observation of learners' metacognitive behavior, and identification of pivotal events. Teacher noticing ability is generally not related to years of experience, but can be learned through participation in sustained, multilevel professional development with an explicit focus on noticing ability. This complex learning integrates teachers' pedagogical and content knowledge with observation of student behaviors, and supports teachers' learning from practice.     

Gender ratios in high school science departments: The effect of percent female faculty on multiple dimensions of students' science identities

To examine how school characteristics are tied to science and engineering views and aspirations of students who are underrepresented in science and engineering fields, this mixed‐methods study explores relationships between aspects of students' science identities, and the representation of women among high school science teachers. Quantitative analyses tested the hypothesis that percent female faculty would have a positive effect on girls' science interests, and perceptions in particular, given the potentially greater availability of women role models. Findings indicate that percent female science faculty does not have an effect on a range of science measures for both male and female students, including the ways in which they understand scientific practice, their science self‐concept, and their interest in science‐related college majors. As qualitative data demonstrate, this could reflect practical constraints at schools where female faculty are concentrated and narrow perceptions of science teachers and “real” science. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 44: 980–1009, 2007     

Distance education plans: Course planning for online adult learners

Summary There can be an untethered excitement connected with ever-expanding technologies and the vastness of educational opportunities that online learning generates. Yet, these new and exciting opportunities do not diminish the real-life concerns and issues that online professors face. Lack of planning often sets the stage for disastrous educational experiences. Problems with technology, the lack of professor guidance and the inability to build community, facilitate communication or humanize learning can sabotage educational efforts. Minimal or nonexistent evaluation can lead to a recycling of futile educational efforts in future online courses. Yet, you can circumvent these issues with proper planning-with the use of distance education plans     

Conceptual difficulties experienced by senior high school students of electrochemistry: Electric circuits and oxidation-reduction equations

The purpose of this research was to investigate students' understanding of electrochemistry following a course of instruction. A list of conceptual and propositional knowledge statements was formulated to identify the knowledge base necessary for students to understand electric circuits and oxidation-reduction equations. The conceptual and propositional knowledge statements provided the framework for the development of a semistructured interview protocol which was administered to 32 students in their final year of high school chemistry. The interview questions about electric circuits revealed that several students in the sample were confused about the nature of electric current both in metallic conductors and in electrolytes. Students studying both physics and chemistry were more confused about current flow in metallic conductors than students who were only studying chemistry. In the section of the interview which focused on oxidation and reduction, many students experienced problems in identifying oxidation-reduction equations. Several misconceptions relating to the inappropriate use of definitions of oxidation and reduction were identified. The data illustrate how students attempted to make sense of the concepts of electrochemistry with the knowledge they had already developed or constructed. The implications of the research are that teachers, curriculum developers, and textbook writers, if they are to minimize potential misconceptions, need to be cognizant of the relationship between physics and chemistry teaching, of the need to test for erroneous preconceptions about current before teaching about electrochemical (galvanic) and electrolytic cells, and of the difficulties experienced by students when using more than one model to explain scientific phenomena.     

Schemata and Intuitions in Combinatorial Reasoning

The problem that inspired the present research refers to the relationships between schemata and intuitions. These two mental categories share a number of common properties: ontogenetic stability, adaptive flexibility, internal consistency, coerciveness and generality. Schemata are defined following the Piagetian line of thought, either as programs for processing and interpreting information or as programs for designing and performing adaptive reactions. Intuitions are defined in the present article as global, immediate cognitions. On the basis of previous findings (Fischbein et al., 1996; Siegler, 1979; Wilkening, 1980; Wilkening & Anderson, 1982), our main hypothesis was that intuitions are always based on certain structural schemata. In the present research this hypothesis was checked with regard to combinatorial problems (permutations, arrangements with and without replacement, combinations). It was found that intuitions, even when expressed as instantaneous guesses, are; in fact, manipulated'behind the scenes' (correctly or incorrectly) by schemata. This implies that, in order to influence, didactically, students' intuitions, those schemata on which these intuitions are based should be identified and acted upon.     

Catching sight of talk: Glimpses into discourse groups

This article reports on a study conducted in a graduate teacher research class with elementary and secondary classroom teachers. Wanting to create a collaborative environment in which their students could use language to support each other's learning, the instructors formed discourse groups. The article introduces a theoretical framework for discourse groups and using examples from the groups, presents a methodology for analyzing the social practices reflected in the teachers’ talk. It concludes with a discussion of the nature of the discourse that supported (and in some cases did not support) the re-storying of teachers’ knowledge.