怎样在化学实验中培养学生的观察能力

化学实验是培养学生观察能力的途径之一.本文就在化学实验中如何培养学生的观察能力提出了具体方法.     

The stability of kindergarten teachers’ effectiveness: A generalizability study comparing the Framework For Teaching and the Classroom Assessment Scoring System

To meet recent accountability mandates, school districts are implementing assessment frameworks to document teachers’ effectiveness. Observational assessments play a key role in this process, albeit without compelling evidence of their psychometric rigor. Using a sample of kindergarten teachers, we employed Generalizability theory to investigate (across teachers, raters, and lessons) the stability of scores obtained with two different observation measures: The CLASS K-3 and the FFT. We conducted a series of Decision studies to document (for both measures’ constituent domains) the number of lessons per teacher and raters per lesson that would justify the use of observation scores for high stakes decisions. Acceptable, stable scores for individual-level decisions about teachers may generally require more raters and lessons than is typically used in practice (1–2 raters and fewer than 3 lessons). The considerable variability of observation-based scores raises concerns about either measure’s appropriateness for making individual or group decisions about teachers’ effectiveness.     

交流等效参数观察法计算三极管放大电路的电压放大倍数

文章提出了计算三极管放大电路电压放六倍数的新方法──交流等效参数观察法,将画微变等效电路的方法求解简化为观察交流等效参数求解．     

谈物理实验中观测能力的培养

物理实验中观测能力的培养是提高学生智力与技能训练重要一环.在大学物理实验中感官训练和思维训练是观测能力培养的主要内容.     

基于MRAS磁链观测、转速估计的无速度传感器异步电机矢量控制系统

针对传统矢量控制系统磁链观测不准,且需要速度传感器的问题,提出了一种基于MRAS磁链观测、转速估计的无速度传感器异步电机矢量控制系统。介绍了磁链观测、转速估计的MRAS结构,并运用Popov超稳定理论推导出了其对应自适应律,建立了实验系统。实验结果表明,该矢量控制系统在启动、调速、稳态运行时具有良好的静、动态性能,是一种高性能的交流调速系统。     

浅谈多视角观察方法

文章主要阐述的是如何通过细节观察、整体观察、动态观察、立体观察等多角度的观察方法来培养学生绘画的整体性和训练创造性思维,提高学生的观察能力,使学生在从事专业设计中拥有新颖、独特的创造能力,更好地把握客观对象的全貌,促进创意思想的表达。     

临近既有线施工路基CFG桩工艺研究

新建长吉城际铁路并行既有长图线,路基地基处理设计为CFG桩,施工工点地势低洼,地下水位高,表土承载力低。为保证施工安全和既有线路基稳定,优化CFG桩施工工艺、采取相应施工方法及监测手段,保证圆满完成施工任务。     

Learning to observe: using video to improve preservice mathematics teachers’ ability to notice

Video has assumed an increasingly prominent role in teacher education, particularly in the form of the viewing of videotaped class lessons by preservice teachers. Yet there is little research that confirms whether preservice teachers attend to the aspects of the video(s) that teacher educators anticipate or desire. This article explores this issue and reports on the impact of video viewing as a means to improve teachers’ ability to be observers of classroom practice. We utilized a pre- and post-test design to measure the quantity and type of classroom events that preservice mathematics teachers noticed before and after a teaching methods course where improving observation skills was an explicit goal. The results of the pre-assessment suggest that preservice teachers generally do not enter teaching methods courses with well-developed observation skills. The post-assessment indicates that the course led to significant increases in preservice teachers’ observation skills, particularly in teachers’ ability to notice features of the classroom environment, mathematical content of a lesson, and teacher and student communication during a lesson.

Enhancing preschool children's vocabulary: Effects of teacher talk before,during and after shared reading

This observational study analyzed patterns of teacher extratextual talk as it occurs before, during, and after reading books to children, and the frequency and duration of teacher questioning by type (label, define, associate) on preschoolers’ receptive and expressive vocabulary knowledge. Over the course of 18 weeks, 13 teachers and 100 children participated in ninety 20-min small-group sessions of teacher-guided shared reading instruction. Teachers’ reading instruction was examined through videotaped observations using the Multi-Option Observation System for Experimental Studies (MOOSES™; Tapp, Wehby, & Ellis, 1995). Two findings, in particular, yielded relevant educational and theoretical implications. First, time spent after reading was significantly related to expressive vocabulary. However, question timing did not seem to matter in terms of receptive vocabulary outcomes. Second, duration of teacher association questioning was significantly related to receptive vocabulary outcomes while both frequency and duration of teacher vocabulary-related association-level questioning were related to expressive vocabulary. For receptive vocabulary, both vocabulary- and comprehension-related association-level questioning mattered. These findings complement the body of work demonstrating that engaging children in interactive shared reading that elicits their active participation is related to meaningful gains in children's language and literacy growth. Limitations of the study and directions for future research are discussed.