Despite the fact that both the Efficient Market Hypothesis and Random Walk Theory postulate that it is impossible to predict future stock prices based on currently available information, recent advances in empirical research have been proving the opposite by achieving what seems to be better than random prediction performance. We discuss some of the (dis)advantages of the most widely used performance metrics and conclude that is difficult to assess the external validity of performance using some of these measures. Moreover, there remain many questions as to the real-world applicability of these empirical models. In the first part of this study we design novel stock price prediction models, based on state-of-the-art text-mining techniques to assert whether we can predict the movement of stock prices more accurately by including indicators of irrationality. Along with this, we discuss which metrics are most appropriate for which scenarios in order to evaluate the models. Finally, we discuss how to gain insight into text-mining-based stock price prediction models in order to evaluate, validate and refine the models. 相似文献
Background: Correct identification of misconceptions is an important first step in order to gain an understanding of student learning. More recently, four-tier multiple choice tests have been found to be effective in assessing misconceptions.
Purpose: The purposes of this study are (1) to develop and validate a four-tier misconception test to assess the misconceptions of pre-service physics teachers (PSPTs) about geometrical optics, and (2) to assess and identify PSPTs’ misconceptions about geometrical optics.
Sample: The Four-Tier Geometrical Optics Test (FTGOT) was developed based on findings from the interviews (n = 16), open-ended testing (n = 52), pilot testing (n = 53) and administered to 243 PSPTs from 12 state universities in Turkey.
Design and Methods: The first phase of the study was the development of a four-tier test. In the second phase of this study, a cross-sectional survey design was used.
Results: Validity of the FTGOT scores was established by means of some qualitative and quantitative methods. These are: (1) content and face validations by six experts; (2) Positive correlations between the PSPTs’ correct scores considering only first tiers of the FTGOT and their confidence score for this tier (r = .194) and between correct scores considering first and third tiers and confidence scores for both of those tiers (r = .218) were found as evidences for construct validity. (3) False positive (3.5%), false negative (3.3%) and lack of knowledge (5.1%) percentages were found to be less than 10% as an evidence for content validity of the test scores. (4) Explanatory factor analysis conducted over correct and misconception scores yielded meaningful factors for the correct scores as an evidence for construct validity. Additionally, the Cronbach alpha coefficients were calculated for correct scores (r = 0.59) and misconception scores (r = 0.42) to establish the reliability of the test scores. Six misconceptions about geometrical optics, which were held by more than 10% of the PSPTs, were identified and considered to be significant.
Conclusions: The results from the present investigation demonstrate that the FTGOT is a valid and reliable instrument in assessing misconceptions in geometrical optics. 相似文献
ABSTRACTIn this paper the authors draw on three sequential keynote addresses that they gave at Active Learning in Engineering Education (ALE) workshops in Copenhagen (2012), Caxias do Sol (2014) and San Sebastian (2015). Active Learning in Engineering Education is an informal international network of engineering educators dedicated to improving engineering education through active learning (http://www.ale-net.org/). The paper reiterates themes from those keynotes, namely, the philosophical and pedagogical underpinnings of Active Learning in Engineering Education, the scholarly questions that inspire engineering educators to go on improving their practice and exemplary models designed to activate the learning of engineering students. This paper aims to uncover the bedrock of established educational philosophies and theories that define and support active learning. The paper does not claim to present any new or innovative educational theory. There is already a surfeit of them. Rather, the aim is to assist Engineering Educators who wish to research how they can best activate the learning of their students by providing a readable, reasonable and solid underpinning for best practice in this field. 相似文献
The authors examined the implementation of written reflections in a Grade 4 mathematics classroom over the course of 8 weeks. Students in this case study engaged in a workshop modeled after Calkin's Writers' Workshop and within this workshop the use of writing as a reflective tool in mathematics was introduced. The authors explore how students used writing to evaluate their learning and how the teacher used the students' written reflections as a formative assessment for instructional purposes. Students' written reflections were coded and these codes were used to conduct an inductive thematic analysis. Analysis of written reflections via constant-comparison analysis was used for further differentiation. The findings show students' ability to accurately self-evaluate their problem-solving skills and highlighted students' confidence level with certain mathematical concepts. Teachers were able to use students' reflections as a place to begin conferring with a student for further clarification. The written reflections aided in instructional decisions and increased individual instruction when needed. The authors include implications for teacher practice and areas for future research. 相似文献
This article concerns the origins of the idea of action learning, especially the claim by Revans that his Memorandum on ‘The Entry of Girls into the Nursing Profession’ in Essex hospitals written in 1938 was the first step in the development of action learning. Whilst Revans repeatedly made this claim, there is no evidence in the actual words of the Memorandum to support it, and he never explained the basis for his belief. Why Revans saw this paper as a first step is therefore a mystery. In this paper we examine the circumstances of the production of the Memorandum to find possible answers. After discussing the evidence we conclude that Revans’ claim is based on the ideas and insights which occurred to him in 1938 in his research and thinking, rather than upon what he actually wrote. We also suggest some defining aspects of action learning can be traced back to ideas first stimulated in the research and production of the 1938 Memorandum, including the importance of first-hand knowledge in tackling organisational problems; the limitations of expert knowledge in complex conditions; the impact of hierarchy on the flow of knowledge; the importance of problem ownership in bring about action for improvement and the primacy of learning in the processes of problem-solving and innovation. 相似文献
Background: Often, a principal’s responsibilities include making decisions about the appropriateness of educational programmes to adopt in their school. Recommendations about programmes can be conflicting; so, a principal may need to search for evidence to inform their decision.Purpose: The purpose of this small-scale study was to clarify how school leaders search for, and use, evidence to inform programme adoption. We sought to answer three research questions: (1) how do principals search for evidence, (2) how do they use common sources and (3) what sources do they consider most useful?Sample: Twelve elementary school principals or vice-principals in Ontario, Canada participated in the study.Design and methods: In telephone interviews, the participants described how they would respond to a fictional decision-making scenario and rated different sources of evidence. Responses were analysed in depth, using a mixed-method approach, which involved coding principals’ interview responses for themes and conducting a dual scaling analysis of their ratings of the usefulness of possible sources.Results: Principals report valuing formal sources of evidence such as reports and articles. However, in practise, findings indicated that they would turn to people first.Conclusions: School leaders prefer curated evidence from local educators to inform their decisions about the appropriateness of educational programmes for potential adoption. 相似文献
