分层回归与经典回归模型比较研究:以顾客资产驱动因素与忠诚意向的关系为例

对我国六大银行688条顾客数据,分别运用两种方法(分层回归模型和经典回归模型)在两种软件(MLwiN 2.10 Beta和SPSS 15.0),进行了数学建模.结果显示,经典回归模型进行参数估计的结果不会产生严重偏差;没有足够的证据证明经典回归模型会因为低估标准误从而使得不显著的变量变得显著.结论表明收集数据时,无论采用分层抽样还是随机抽样,建模者都可以先从建立简单模型着手,获得对数据的初步认知.     

分配格与模格的另一二条件等价定义

针对分配格与模格的格等式定义问题,得知了二条件是定义分配格与模格的最少条件,并进一步证明了Sholander's basis是定义分配格的最短最少变量格等式,最后又从分配格和模格的基本定义出发给出了新的分配格的二条件和三条件等价定义等式及模格的二条件与三条件等价定义等式.     

模糊数在股本权证定价中的应用

采用Ukhov权证定价模型求解权证价值的过程中,需要求解一个非线性方程组．但是采用数值法得到的最优解与精确解往往有一定偏差．针对这个情况,本文采用模糊数刻画非线性方程组的解,得到不确定形式的股本权证定价模型,并给出一定可信度下权证的模糊价格区间．同时也给出了给定任意一个权证价格求其对应的可信度的优化算法．数值算例验证了该文方法的有效性．     

Who succeeds in STEM? Elementary girls' attitudes and beliefs about self and STEM

With ongoing underrepresentation of women in STEM fields, it is necessary to explore ways to maintain girls' STEM interest throughout elementary and middle school. This study is situated within the context of Designs in STEM (pseudonym), an out-of-school program that engages urban youth in authentic STEM experiences. Participants were 30 girls attending Designs in STEM in grades four and five. Participants were interviewed about their STEM interest, out-of-school versus in-school STEM learning experiences, and how gender relates to STEM success. Several key findings emerged. First, although students' prior school experiences with mathematics resulted in less positive dispositions toward mathematics than other STEM disciplines, their experiences at Designs in STEM revealed that mathematics could be fun and valuable when used for real-world purposes. Second, students found Designs in STEM to be more engaging and inspiring due to the context and pedagogies employed by Designs in STEM instructors. Third, despite observing girls' behavior that was more aligned with academic success, participants still identified STEM advantages for boys. Finally, participants defined success and intelligence in STEM based on speed and tracking. Discussion focuses on the need to consider how school-based mathematics instruction may serve as a barrier to girls' STEM interest and involvement.     

成长性差异、信息披露与权益资本成本

本文研究成长性差异是否以及如何影响信息披露与权益资本成本之间的关系。实证结果表明成长性差异可以显著调节信息披露与权益资本成本之间的关系,利用分组回归分析法发现,高成长性上市公司信息披露水平越高,权益资本成本越低。进一步研究发现,在高成长性样本组中,非国有控股上市公司信息披露对权益资本成本的影响相对显著,而在低成长性样本组中,国有控股上市公司信息披露对权益资本成本的影响相对显著。在采用工具变量法和两阶段最小二乘法等(2SLS)进行一系列稳健性检验之后,上述结论仍然成立。本文的研究结论为上市公司和监管机构完善信息披露制度提供一定的启示。     

消费者心理违约对品牌权益的影响机制研究

本文旨在把组织行为学中的心理契约理论应用于市场营销情景下的品牌关系。本文通过把心理违约分成两个阶段,即心理违约(Psychological Contrac(?) Breach)和心理违背(Psychological Contract Violation)来研究消费者心理违约对品牌权益的影响。结果显示,心理违背会负面地影响品牌形象和品牌忠诚。但在心理违约和心理违背之间还存在着其它影响因素,有待进一步的研究。     

面向顾客资产的三维顾客细分模型及其应用

简单依照顾客利润贡献对顾客细分未能充分考虑顾客的无形贡献,会低估顾客对企业的价值.从面向顾客资产的视角进行顾客细分,可以兼顾到顾客当前的利润贡献和顾客的潜在有形和无形贡献,从而提出基于顾客当前显性贡献、潜在显性贡献和潜在隐性贡献三维顾客细分模型及度量方法,并结合实证阐述顾客细分方法的实现过程.     

Inquiry as an entry point to equity in the classroom

ABSTRACT

Although many policy documents include equity as part of mathematics education standards and principles, researchers continue to explore means by which equity might be supported in classrooms and at the institutional level. Teaching practices that include opportunities for students to engage in active learning have been proposed to address equity. In this paper, through aligning some characteristics of inquiry put forth by Cook, Murphy and Fukawa-Connelly with Gutiérrez's dimensions of equity, we theoretically explore the ways in which active learning teaching practices that focus on inquiry could support equity in the classroom.     

Promoting Equitable Biology Lab Instruction by Engaging All Students in a Broad Range of Science Practices: An Exploratory Study

This study examines what students enrolled in the honors and general sections of a high school biology course offered at the same school learn when they have an opportunity to participate in a broad or narrow range of science practices during their laboratory experiences. The results of our analysis suggest that the students enrolled in the general sections of the course made similar or larger gains than the students enrolled in the honors section of the course in their abilities to plan and carry out an investigation, argue from evidence, and write a science‐specific persuasive essay when these students had an opportunity to participate in a broad range of science practices. These findings suggest that laboratory experiences that give students an opportunity to participate in a broad range of science practices, although considered challenging by many teachers, have the potential to help all students become more proficient in science. The article concludes with a discussion of the implications of this study for classroom instruction and educational policy.     

Preservice Secondary Mathematics Teachers' Conceptualizations of Equity: Access and Power as Seen Through Vignette Responses

Attention to equity in the mathematics education field has been growing in recent years. We have evidence that many novice secondary mathematics teachers do not feel prepared to teach in regards to diverse populations. We need to know more about how secondary preservice mathematics teachers (PSMTs) conceptualize equitable environments. This study investigates 30 secondary PSMTs' proposed responses to two hypothetical vignettes from mathematics department conversations regarding calculator usage and mathematical discourse, respectively, utilizing two of Gutiérrez's four dimensions of equity: Access and Power. Results suggest these PSMTs considered equity, equality, and creating a classroom that invites participation among other factors when thinking of an equitable approach with respect to calculator usage. When considering mathematical discourse, PSMTs cited the need to “model” proper use of mathematical language as well as to allow students to themselves verbalize it. Implications mathematics education and teacher education more broadly are to integrate equity and equality discussions in methods courses and to include strategies to facilitate productive discourse.