Reasoning about data in middle school science

This case study illustrates instruction in an urban 6th‐grade classroom in which students were learning about mass, volume, and density by attempting to layer (stack) three miscible solutions with differing densities atop one another. The study examines classroom discourse and interaction on the basis of four teaching goals: (a) reaching consensus about which stacks were possible, (b) developing persuasive arguments that separated data from noise, (c) establishing social norms for collective inquiry, and (d) appreciating the epistemological status of scientific knowledge. The study traces the fate of three stacks that students claimed were possible after initial investigations with the solutions. These claims underwent a process of collective validation in which consensus without coercion was the goal, which illustrates emergent standards for backing claims with evidence, as well as for replicability, among the students. Students were successful in achieving three of the four goals, with some qualifications. In relation to Goal 3, which required generalization to other situations, somewhat less success is reported. Limitations in the current standards, difficulties of time allotment in current curricula, and establishing classroom cultures of inquiry are discussed. © 1999 John Wiley & Sons, Inc. J Res Sci Teach 36: 179–199, 1999     

关于推理能力问题的几点思考

推理能力的培养是义务教育教学课程的核心目标之一，推理能力主要包括合情推理与逻辑推理2种，而推理能力的培养途径是多方面的，它不仅可以通过几何的教学来实现，在代数、统计等领域中也可以进行推理的训练。在培养学生推理能力的过程中，要注重培养学生通过观察、实验、归纳、类比等获得数学猜想的能力；寻求证据，给出证明或举出反例的能力；以及有条理地表达自己思考过程的能力和用数学语言合乎逻辑地进行讨论与质疑的能力。     

论科学发现中灵感的逻辑建构

灵感具有鲜明的逻辑性、某种意义上可以说灵感的过程也是逻辑的过程－在灵感过程的诱发、诱发、生发阶段，逻辑始终占据了主导地位，发挥着支配的作用。在此基础上，笔者构筑了触发灵感的模型和灵感及其逻辑因素的函数。     

明故知类有所止而正－中国古代逻辑中关于“说”的谬误

西方传统逻辑讲谬误，主要指形式谬误；中国古代逻辑讲谬误，主要指实质谬误。中国古代逻辑中关于“说”的谬误，主要指非必然性推理的错误。由于在推理的过程中不知类，不明故或不知止，就会产生各种实质性谬误。古代逻辑学不仅分析了产生谬误的原因，而且分析了不同的谬误形式，这些探索和分析有助于我们进一步提高思辩能力，防止逻辑错误。     

Reasoning about Interactions between Variables

Thinking about interactions between variables is a necessary condition for accurate scientific thinking. The purpose of this study was to investigate difficulties in thinking about interactions between variables and to suggest remedial educational means. A conceptual analysis distinguishes between valid interaction inferences, invalid interaction inferences, and limited inferences which can be seen as a partial or a primitive interaction inference. Empirical findings show that expert thinkers demonstrate thinking about interactions at both an operational and a metastrategic level. Some lay-adults however, although able to draw many limited inferences, encounter substantial difficulties in drawing valid interaction inferences while engaged in an investigation of a scientific sort. Four types of difficulties were identified in this study: lack of a “double set of controlled comparisons” strategy that is necessary for valid inferences about interacting variables; lack of the conceptual framework for interacting factors; diversion of attention to other features; and difficulty in maintaining the necessary control of other variables. The implications of the findings to science curriculum are discussed.     

Children's Gender-Based Reasoning about Toys

The goal of these studies was to investigate how preschool children use gender-based reasoning in making judgments about toy preferences for themselves and for others. In Studies 1 and 2, children ( n = 22, n = 71) were shown unfamiliar, non-sex-typed toys and asked to rate how much they, other girls, and other boys would like each toy. As expected, children made gender-based inferences: "What I like, children of my sex will also like, and children of the other sex will not like." Study 3 was designed to assess how children use gender-based reasoning to make decisions about attractive and unattractive toys when they are given gender labels. Children ( n = 91) were shown unfamiliar toys varying in attractiveness that were given explicit gender labels (e.g., "this is a toy girls really like") or no label. With a different experimenter (to avoid demand characteristics), children rated their own and others' liking of the toys. Children used gender labels to guide their own preferences and their expectations for others. Even with very attractive toys, children liked toys less if they were labeled as being for the other sex, and expected other girls and boys to do the same. The role of gender-based reasoning in cognitive theories of gender and on children's play preferences is discussed.     

Children's Reasoning about Interpersonal and Moral Conflicts

2 studies were conducted to determine if children make judgments about both justice and interpersonal relations in conflictful situations. In Study 1, 48 subjects (24 males and 24 females) in the third, sixth, and ninth grades (mean ages = 8.40, 11.38, 14.38 years) were administered 2 stories entailing conflicts between justice and interpersonal concerns. Children judged and justified acts in 4 conditions systematically varying interpersonal and justice concerns. Children generally gave priority to justice and rights over friendship, based primarily on considerations of welfare or rights. In Study 2, 76 subjects (39 males and 37 females) in the third, sixth, and ninth grades (mean ages = 9.08, 12.10, 14.92 years) were presented with 3 stories entailing conflicts between justice and interpersonal relations. Subjects gave greater priority to interpersonal considerations in Study 2 than in Study 1, and their evaluations varied according to the salience of the different concerns. In both studies, few gender differences were obtained. The results demonstrate that across development, concerns with justice and interpersonal relationships coexist in judgments of male and female children, and that the ways they are applied depend on the situation.     

Affective profiles and academic success in a college science course

The current study identified affective profiles and examined their relations to behavioral engagement and disengagement as well as achievement among undergraduate students enrolled in a college anatomy course (N = 278). Cluster analysis was used to identify four affective profiles: Positive, Deactivated, Negative, and Moderate-Low. Students in the Positive and Deactivated profiles were more engaged, less disengaged, and earned higher grades on subsequent exams than those in Moderate-Low and Negative profiles, which did not differ from one another. Subsequent analyses indicated that the relation of affective profiles to achievement was mediated through engagement. Results provide support for the importance of examining students’ mixed affective experiences in terms of both valence and activation dimensions, adding important contributions to largely variable-oriented literature on academic affect and its relation to engagement and achievement.     

关于555定时器逻辑功能的讨论

从基本RS触发器功能出发,对555定时器的逻辑功能进行了讨论,认为555集成定时器高电平触发端加小于2Ucc /3的电平,低电平触发端加小于Ucc /3的电平时,触发器置"1".     

Moral Reasoning about Sexually Transmitted Diseases

The purpose of this research was to investigate moral reasoning related to sexual behavior that could lead to the transmission of sexually transmitted diseases (STDs). Using hypothetical dilemmas about situations in which STDs can be transmitted, respondents were asked to explain why they believed the characters should or should not engage in risky behaviors. 40 college freshmen ( M = 18.3 years) and 32 college seniors ( M = 22.3 years) participated. Using Kohlberg's moral stage theory and Gilligan's moral orientation model, the interviews were scored for moral stage and moral orientation. Results indicated that the older age group had a significantly higher stage of moral reasoning than the younger age group when responding to dilemmas about STDs. There was a significant difference in moral stage between dilemmas, reflecting the possible effect of dilemma content on moral reasoning. The overall pattern of results shows nonsignificant gender differences in stage of moral reasoning and moral orientation. Clinical and theoretical implications of these findings for understanding the role of moral reasoning in sexual risky behavior are discussed.     

Children's Reasoning about Video and Real Balance-Scale Problems

Research findings: 3- and 5-year-old children's television-viewing was recorded for 2 years, then their rules for solving videotaped and real balance-scale problems were assessed. Older children used more advanced rules than younger children. Those who saw the videotaped version first used less advanced rules on it than on the real version. Those who saw the real problems first did not differ between versions. Neither verbal IQ, nor family demographics, nor television-viewing predicted 5- or 7-year-olds' rules on real problems. However, 7-year-olds' rules for solving video problems were positively related to parents' ratings of how often their child engaged in TV-focused social interactions. TV focus accounted for the effects of order of administration on the video problems. Cartoon-viewing at age 7 was negatively correlated with using rules on the video. Once cartoon-viewing at 7 was accounted for, cartoon-viewing at age 5 emerged as a positive predictor of rule use on the video. The results are more consistent with mental effort than media literacy. Implications for practice: Parents should encourage TV-focused social interactions and educators should begin with real demonstrations, then proceed to video-mediated instruction.     

儿童归纳推理的多样性效应及其争论

儿童在归纳推理中是否遵循多样性原则,表现出多样性效应,这个问题一直存在争论。在Lopez等、Gutheil等和李富洪等的研究中,小于9岁儿童的归纳推理不遵循多样性原则。Heit等的研究中,5岁儿童却表现出了一定的多样性效应。而Lo等更是基于贝叶斯模型,提出了用前提概率与论断力度的关系(即ppp)来衡量儿童运用多样性信息的能力。事实上,儿童归纳推理多样性效应的争论是由推理范畴的不同所引起,一种是涉及生物概念范畴,另一种是涉及人格特质概念范畴。在人格特质概念范畴中,可以运用心理理论、人格特质与行为之间稳定的关系,以及共变原则的归因促进儿童对前提多样性信息的运用。     

Reasoning from data: How students collect and interpret data in science investigations

This study explored the understandings of data and measurement that school students draw upon, and the ways that they reason from data, when carrying out a practical science inquiry task. The two practical tasks used in the study each involved investigations of the relationships between two independent variables (IVs) and a dependent variable (DV); in both tasks, one IV covaried with the DV, whereas the other did not. Each was undertaken by 10 students, aged 10, 12, and 14 years (total n = 60 students), working individually. Their actions were video‐recorded for analysis. In a subsequent interview, each student was asked to discuss and interpret data collected by two other students, undertaking a similar (but different) practical task, shown on a video‐recording. An analysis of the sample students' performance on the practical tasks and their interview responses showed few differences across task contexts, or with age, in students' reasoning, but significant differences in performance when investigating situations of covariation and non‐covariation. Few students in the sample displayed sufficient understanding of measurement error to deal effectively with the latter. Investigations of non‐covariation cases revealed, much more clearly than investigations of covariation cases, the students' ideas about data and measurement, and their ways of reasoning from data. Such investigations therefore provide particularly valuable contexts for teaching and research. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 748–769, 2004     

Secondary science teachers' attitudes toward and beliefs about science reading and science textbooks

Science textbooks are dominant influences behind most secondary science instruction but little is known about teachers' approach to science reading. The purpose of this naturalistic study was to develop and validate a Science and Reading Questionnaire to assess secondary science teachers' attitudes toward science reading and their beliefs or informed opinions about science reading. A survey of 428 British Columbia secondary science teachers was conducted and 215 science teachers responded. Results on a 12-item Likert attitude scale indicated that teachers place high value on reading as an important strategy to promote learning in science and that they generally accept responsibility for teaching content reading skills to science students. Results on a 13-item Likert belief scale indicated that science teachers generally reject the text-driven model of reading, but they usually do not have well-formulated alternative models to guide their teaching practices. Teachers have intuitive beliefs about science reading that partially agree with many research findings, but their beliefs are fragmented and particularly sketchy in regard to the cognitive and metacognitive skills required by readers to learn from science texts. The findings for attitude, belief, and total scales were substantiated by further questions in the Science and Reading Questionnaire regarding classroom practice and by individual interviews and classroom observations of a 15-teacher subsample of the questionnaire respondents.     

Children's Reasoning about the Interaction of Forces

In order to acquire an advanced understanding of movements caused by more than one physical force, children must learn to combine force vectors. Former studies suggest that children consider information on only one aspect (direction or amount) of both vectors. Two experiments tested this hypothesis. A total of 160 elementary school children and 31 adults judged the effect of two forces pulling at one object simultaneously. Participants had to predict the direction of the resulting force under different experimental conditions. In line with previous findings, most children took into account either the direction or the amount of both forces. Their preferred solution varied with the nature of the vector problem and the context of the task. Performance generally improved with age.     

突出逻辑推理 加强应用能力考查——2014年全国高考数学试题评析

2014年高考数学试题以能力立意,稳中有新,体现了新课标的精神,体现了科学性、规范性和基础性的特点。试卷体现高考改革的方向,突出逻辑思维能力,重视考查考生的应用意识和创新意识,准确区分考生,有利于科学选拔人才,有利于学生健康成长,有利于促进社会公平。     

浅谈数学概念教学中学生创新思维的培养

数学概念是数学教学中培养学生创新思维的重要环节 ,文章从概念的引入、形成、表达、巩固和实际运用等五方面浅谈在概念教学中优化学生的创新心理 ,培养学生创新思维和能力的具体运作。     

谈谈初中化学中物质与混合物的逻辑关系

本文讨论了初中化学中物质与混合物之间两组相互矛盾的命题,找出了造成逻辑错误的原因,澄清了由于物质这一概念的外延不定使某些概念含混不清的现象。