A fast splitting procedure for classification trees

This paper provides a faster method to find the best split at each node when using the CART methodology. The predictability index is proposed as a splitting rule for growing the same classification tree as CART does when using the Gini index of heterogeneity as an impurity measure. A theorem is introduced to show a new property of the index : the for a given predictor has a value not lower than the for any split generated by the predictor. This property is used to make a substantial saving in the time required to generate a classification tree. Three simulation studies are presented in order to show the computational gain in terms of both the number of splits analysed at each node and the CPU time. The proposed splitting algorithm can prove computational efficiency in real data sets as shown in an example.     

发展健康的情感依附

保育员和孩子之间的情感依附至关重要 根据Sroufe在明尼苏达大学于2000年所做的研究显示,在早期儿童发展期中,父母或保育员与孩子建立正常的依附关系,对孩子整个童年和青春期都有重大的影响.从孩子的依附过程,可以看得出他日后在学校是否成功、在精神和行为上是否能正常地发展.     

人脑绘图与儿童学习的方法

神经科学家已经能够用特别的仪器,把人脑的活动测绘记录下来.这种革新技术让我们能一窥人的思想,而其中每种技术也都各有长处.     

Adolescent Perception of Sex-Roles in 1968 and 1975

Findings from a study of 798 sixth- and seventh-grade studentsin Milwaukee in 1974–75 were compared to those from astudy of 470 Baltimore sixth- and seventh-grade children in1968 to see if the new feminist ideology has had an effect ongirls' self-esteem and attitudes toward their own sex. Resultsindicate few differences between the two studies. Girls in 1974–75still demonstrated lower self-esteem and a less high evaluationof their sex-role than did their male counterparts