An analysis of the nature of epistemological beliefs: Investigating factors affecting the epistemological development of south korean high school students

The purpose of this study is to investigate the nature of epistemological beliefs about learning (or learning beliefs) by analyzing the type of factors involved in the epistemological development of South Korean high school students (N=455). Learning beliefs are implicit assumptions held by learners about the source and certainty of knowledge and the ways to obtain knowledge. Previous studies on the epistemological development of American high school students showed that American students learning beliefs are positively related with their age, amount of formal education, and academic achievement. Multiple regression analysis of this study, however, showed that no such relationships were identified from the present South Korean sample except between students beliefs and their academic achievement. In addition, the present study showed that South Korean students learning beliefs were related with their independent-self construal (individualistic self-view) but not with their interdependent self-construal (collectivistic self-view). These results reconfirmed the culture-specific nature of epistemological beliefs which was identified from previous comparative studies with South Korean and American college students (Youn, Kim, & Yang, 1999; Youn, 2000). The differences between the present results and previous findings with South Korean college students will be further discussed in terms of the sub-cultural variations between South Korean young generations. A paper presented at the 26th International Association of Cross Cultural Psychology, Pultusk, Poland, 2000/7/16-21     

Decentralized adaptive output-feedback control of interconnected nonlinear time-delay systems using minimal neural networks

This paper presents a minimal-neural-networks-based design approach for the decentralized output-feedback tracking of uncertain interconnected strict-feedback nonlinear systems with unknown time-varying delayed interactions unmatched in control inputs. Compared with existing approximation-based decentralized output-feedback designs using multiple neural networks for each subsystem in lower triangular form, the main contribution of this paper is to provide a new recursive backstepping strategy for a local memoryless output-feedback controller design using only one neural network for each subsystem regardless of the order of subsystems, unmeasurable states, and unknown unmatched and delayed nonlinear interactions. In the proposed strategy, error surfaces are designed using unmeasurable states instead of measurable states and virtual controllers are regarded as intermediate signals for designing a local control law at the last step. Using Lyapunov stability theorem and the performance function technique, it is shown that all signals of the total controlled closed-loop system are bounded and the transient and steady-state performance bounds of local tracking errors can be preselected by adjusting design parameters independent of delayed interactions.     

A synthesis on the research of the comorbidity of ADHD and LD in Korea: perspective and trend

Attention-deficit/hyperactivity disorder (ADHD) and learning disabilities (LD) are the most commonly diagnosed childhood disorders, and they frequently co-occur with each other. It has been found that students with comorbidity of ADHD and LD experience more difficulties in school. Even though the research interests in the comorbidity of ADHD and LD are increasing, there are inconsistent results in research studies and insufficient understanding of the comorbidity of ADHD and LD. This study attempts to grasp the progress of the studies in the comorbidity of ADHD and LD in Korea and to suggest the future directions for following research. A total of 90 studies published between 1987 and 2009 are examined. First, we analyze the studies that examined the learning problems of ADHD and then identify the characteristics of the learning problems in ADHD group. Afterwards, we investigate the studies that dealt with the attention problems of LD and then discuss the characteristics of the attention problems in LD group. Third, we identify the differences between ADHD and LD and synthesize the research findings. Finally, we analyze the studies conducted in conjunction with the comorbidity of ADHD and LD. On lightening the research of the comorbidity on three aspects, we find the research trend in Korea and provide the implications for future studies on the comorbidity of ADHD and LD. Furthermore, we suggest that it is important to identify comorbid conditions at the early stage, and it is necessary to conduct multidisciplinary research and international comparison research.     

Understanding Complex Ecosystems Through an Agent-Based Participatory Watershed Simulation

Journal of Science Education and Technology - The properties and functions of complex systems apply across a variety of domains of science and are at the heart of the solutions to many global...     

How day of posting affects level of critical discourse in asynchronous discussions and computer-supported collaborative argumentation

In asynchronous threaded discussions, messages posted near the end of the week provide less time for students to critically examine and respond to ideas presented in the messages than messages posted early in the week. This study examined how the day in which messages are posted (early, midweek and weekend) in computer-supported collaborative argumentation affect the number of responses elicited by arguments and challenges, and how its effects differ across the four types of exchanges (argument–challenge, challenge–counterchallenge, challenge–explain, challenge–evidence) that serve as indicators of critical discourse. This study found that the day of posting had a significant effect on the number of responses elicited per message, with the greatest to smallest effect on argument–challenge, challenge–counterchallenge, challenge–explain and challenge–evidence exchanges respectively. These findings highlight some of the limitations of asynchronous discussions, and suggest alternative ways to implement and design discussion environments to promote higher levels of critical discourse.     

The effectiveness of using computer simulated experiments on junior high students' understanding of the volume displacement concept

Several researchers have suggested that the computer holds much promise as a tool for science teachers for use in their classrooms (Bork, 1979, Lunetta & Hofstein, 1981). It also has been said that there needs to be more research in determining the effectiveness of computer software (Tinker, 1983). This study compared the effectiveness of microcomputer simulated experiences with that of parallel instruction involving hands-on laboratory experiences for teaching the concept of volume displacement to junior high school students. This study also assessed the differential effect on students' understanding of the volume displacement concept using sex of the students as another independent variable. In addition, it compared the degree of retention, after 45 days, of both treatment groups. It was found that computer simulated experiences were as effective as hands-on laboratory experiences, and that males, having had hands-on laboratory experiences, performed better on the posttest than females having had the hands-on laboratory experiences. There were no significant differences in performance when comparing males with females using the computer simulation in the learning of the displacement concept. This study also showed that there were no significant differences in the retention levels when the retention scores of the computer simulation groups were compared to those that had the hands-on laboratory experiences. However, an ANOVA of the retention test scores revealed that males in both treatment conditions retained knowledge of volume displacement better than females.     

Data‐driven refinements of a genetics learning progression

Learning progressions are theoretical models that describe learning of scientific ideas and practices over time. These hypothetical progressions need to be tested and refined in order to productively inform instruction and assessment. In this paper, we report our attempts to revise a learning progression in genetics. In particular, we focused on two constructs that embody core ideas in classical genetics and one molecular construct. The revisions are based on analysis of pre‐ and postinterview data obtained from sixty 11th grade students before and after they engaged in a 10‐week unit that addressed these concepts. We found that while many of the students held ideas that aligned with the progression, there were several distinct dimensions of student reasoning that were not captured and led to substantial revisions of the constructs including: (a) the splitting of the construct dealing with meiosis (E) into two subconstructs (E1‐physical passage of genetic information and E2 – the role of sex cells), (b) the addition of new levels to constructs dealing with the universal nature and organization of the genetic code (A) and construct (F). For Construct A, the lower levels were expanded to include ideas about the localization of DNA in cells and to include ideas about the composition of DNA that were not captured in the progression. Revisions to Construct F included the expansion of existing levels and the addition of modes of inheritance such as codominance and incomplete dominance. The research we present offers insights about a methodological approach that can be used to test and refine progressions, as well as insights about student learning in genetics as we further describe and expand the stepping‐stone ideas in the progression and discuss further the multidimensional nature of learning progressions.     

Solving Hitchcock’s transportation problem by a genetic algorithm

IntroductionTheHitchcock’sTransportationProblem(HTP)canbeformulatedasaclassiclinearprogrammingprobleminwhichthesetofconstraintsisofaspecialstructure[1,2].TheHTPisapracticaltransportationprobleminproductiondistributionsector.Alotofpracticaltrans-portationandassignmentproblems,suchastheminimumcostroadnetworktrafficflowproblemwithsolidchargeinlogistics,canbeformulatedinthisway,anditisclearlythattheHTPmaybehasmorethanoneoptimalsolution.Itisveryimportantforadecision-makertoselectafavorableone…