The impact of student misconceptions on student persistence in a MOOC     

Chen Chen  Gerhard Sonnert  Philip M. Sadler  Dimitar Sasselov  Colin Fredericks 《科学教学研究杂志》2020,57(6):879-910

Massive Online Open Courses (MOOCs) provide opportunities to learn a vast range of subjects. Because MOOCs are open to anyone with computer access and rarely have prerequisite requirements, the range of student backgrounds can be far more varied than in conventional classroom-based courses. Prior studies have shown that misconceptions have a huge impact on students' learning performance; however, no study has empirically examined the relationship between misconceptions and learning persistence. This study of 12,913 MOOC-takers examines how students' misconceptions about the upcoming course material affect course completion. Using a survival analysis approach, we found that, controlling for the score in a pre-course test, students holding more misconceptions had a higher dropout rate at the start of the course, an effect that diminished over time. Other student variables were found to have a positive impact on survival that persisted throughout the entire course: U.S. location, higher age, an intention to complete, better English skills, prior familiarity with the subject, motivation to earn a certificate, and score and time spent on the previous problem set (homework). By contrast, student gender, education level, number of previous MOOCs completed, and motivation to participate in online discussion forums did not affect survival.  相似文献   

平行泊车路径规划算法研究及验证     

王瑞  孙涛  赖杰 《教育技术导刊》2020,19(4):119-124

路径规划算法研究是自动泊车系统中最常见的问题之一。为解决平行泊车场景下,车辆泊车入位较难的问题,采用反向推导法,理论分析泊车过程并推导了路径规划函数公式,在确定泊车起点后,能够安全引导车辆进入泊车位。首先建立车辆模型,在确定碰撞约束和最优目标函数后,推导了车辆三阶段单向行驶泊车路径;然后针对单向泊车路径规划中要求车位长度较长的问题,提出四阶段行驶路径规划方法;最后,根据实际车辆及车位信息,利用Matlab软件与实验车平台,分别验证了该路径规划方法的有效性。实验结果表明,采用双向四阶段泊车方式相比单向三阶段泊车方式,对车位长度的要求缩短了0.26m。  相似文献   

新时代科研范式变革的内涵及应对          下载免费PDF全文

杜鹏  赵秉钰  孙粒  沙小晶  张理茜  王孜丹 《中国科学院院刊》2023,38(7):991-1000

文章从理论和实践层面对科研范式变革的主要内涵和重要影响进行综合性探讨。在理论层面上,从库恩及其代表作《科学革命的结构》入手,探讨“范式”概念的逻辑本质。在实践层面上,通过问卷调查和访谈等形式,调研、凝练出新时代科研范式变革的3个方面内涵：解决系统性复杂问题成为新时代科研范式变革主要驱动力,仿真模拟和数据科学可能成为推动科研范式变革的有效突破口,科研活动组织创新成为推动科研范式变革的基础。在此基础上,分析目前我国应对科研范式变革存在的问题,并提出相应的政策建议。  相似文献   

取消左转可缓解交通拥堵的计算机仿真     

石文堂  曾沥锋  汪祖民 《中国科技信息》2010,(3):256-257,262

围绕三排道十字信号交叉口取消左转弯的管理措施,建立了计算机仿真模型。结合概率论与数理统计方法对车辆生成模型进行泊松分布假设检验,选取通行能力作为判定指标,实现了禁左前后通行能力的对比．  相似文献   

产业集群网络上的知识转移分析——以南京大明路汽车销售与服务产业集群为例   总被引：4，自引：0，他引：4  

陈金丹  胡汉辉 《科学学与科学技术管理》2010,31(2)

集群知识转移是集群企业获取竞争力的关键,也是集群创新与发展的重要一环。产业集群网络作为集群知识转移的背景环境,其网络结构必然影响知识转移。将谣言模型引入到集群知识转移的研究中,在应用社会网络分析方法分析南京大明路汽车销售与服务产业集群网络的基础上,采用基于Agent的数值仿真技术对集群网络上的知识转移过程进行仿真与对比性分析,给出集群网络的优化方向。  相似文献   

边界吸收中镶边法的评价   总被引：10，自引：0，他引：10  

陈可洋 《中国科学院研究生院学报》2010,27(2):170-175

以均匀层状带凹陷特征的介质模型为例,分析镶边法在常规边界吸收问题中的独到优越性;采用均匀倾斜模型数值实例,详细探讨外侧镶边法在边界吸收中的弊端及其成因.综合数值试算分析表明,外侧镶边法会引入虚假反射波,其原因是边界处速度延拓产生了人为绕射点.提出了内侧镶边方法,即以牺牲局部有效波场来提高数值计算精度、信噪比和可信度,实例验证该方法正确可行.  相似文献   

寒区路基工程与多年冻土间的相互作用分析     

朱正刚  钱江  李南生 《科技通报》2010,26(1):138-142

基于Harlan一维水热耦合模型对多年冻土地区水分场、温度场耦合计算进行探讨,建立了水热耦合二维物理模型。对该模型采用伽辽金有限元法和隐式有限差分数值离散,结合某实际高原铁路路基工程进行数值计算,分析了修筑铁路路基对原天然路面热稳定的影响,并对未来十年内全球气候变暖对路基的影响进行了数值模拟,考察了多年冻土上限的变化情况。结果表明：铁路路基改变了原天然地面的传热形式,因而有条件地提高了路基下多年冻土上限,而全球气候的变暖,将对建筑在多年冻土上的铁路路基热稳定性产生影响。  相似文献   

基于AHP-模糊综合评价方法的企业重组财务协同效应分析   总被引：1，自引：0，他引：1  

党凌云  党云霞 《科技创业月刊》2010,23(4):45-47

财务协同效应分析对于企业重组尤其是并购重组来说是一个具有战略性意义的问题。通过构建评价指标体系,综合运用层次分析法(AHP)和模糊综合评价方法,以国美并购永乐为例对企业重组的财务协同效应进行评价分析,得出该并购重组财务协同效应状况为良好的结论。该方法对于评价企业重组财务协同效应具有很好的实际意义和应用价值。  相似文献   

Initiating private-collective innovation: The fragility of knowledge sharing     

Simon Gächter 《Research Policy》2010,39(7):893-906

Incentives to innovate are a central element of innovation theory. In the private-investment model, innovators privately fund innovation and then use intellectual property protection mechanisms to appropriate returns from these investments. In the collective-action model, public subsidy funds public goods innovations, characterized by non-rivalry and non-exclusivity in using these innovations. Recently, these models have been compounded in the private-collective innovation model where innovators privately fund public goods innovations. Private-collective innovation is illustrated in the case of open source software development. This paper contributes to the work on this model by investigating incentives that motivate innovators to share their knowledge in an initial situation, before there is a community to support the innovation process. We use game theory to predict knowledge sharing behavior in private-collective innovation, and test these predictions in a laboratory setting. The results show that knowledge sharing is a coordination game with multiple equilibria, reflecting the fragility of knowledge sharing between innovators with conflicting interests. The experimental results demonstrate important asymmetries in the fragility of knowledge sharing and, in some situations, more knowledge sharing than theoretically predicted. A behavioral analysis suggests that knowledge sharing in private-collective innovation is not only affected by material incentives, but also by social preferences such as fairness. The results offer general insights into the relationship between incentives and knowledge sharing and contribute to a better understanding of the initiation of private-collective innovation.  相似文献   

Relationship quality,community promotion and brand loyalty in virtual communities: Evidence from free software communities     

Luis V. Casaló  Carlos Flavián  Miguel Guinalíu 《International Journal of Information Management》2010

The Internet has favored the growth of collaborative platforms where marketers and consumers interact to develop more engaging products and services. These platforms are usually centered in a specific brand/product and their members are linked by a shared admiration to that brand. This paper analyzes one of the most powerful online collaborative platforms, the free software (FS) case, which involves a lot of virtual communities developed around products such as Linux or Android, the new Google's mobile operating system. Our purpose is to determine some of the main antecedents and consequences of the consumer involvement in this type of communities. Results have shown that satisfaction with a virtual community may increase the level of consumer participation in that community. At the same time, a greater identification with the virtual community may increase indirectly the consumer participation thanks to the enhancement of his/her satisfaction with the community. We have also found positive and significant effects of consumer identification and participation on the level of community promotion. Finally, positive and significant effects of consumer participation and satisfaction with the community on loyalty to the FS were also found. These findings allow us to conclude some interesting managerial implications.  相似文献