Hierarchical Modeling Method Research Articles

HSM-Simulation–Based Planning Method for Construction Projects

Construction projects are characterized by the random nature of the conditions under which they are implemented and by the dynamic use of available resources. Since site conditions vary randomly and resources perform a multitude of functions on various work tasks, planning of construction projects using traditional tools like the critical path method becomes limited and induces deficiency in the resulting plan. This paper demonstrates that a simulation-based methodology is appropriate for modeling such a scenario. The hierarchical simulation modeling (HSM) method, a simulation-based method, for planning of construction projects is presented. HSM enhances and combines the concepts of work breakdown structure and process modeling to arrive at an advanced framework for planning. Hierarchical and modular simulation constructs form the basis of this method. The construction of a bridge (Peace River Bridge) is used to illustrate HSM concepts and its advantages.

Hierarchical Models for Educational Data: An Overview

The use of hierarchical models in statistical applications, and for educational data, is a promising but still underutilized approach. However, because these models are more complicated than many standard methods, it is important that we, as users and developers, not rush to use them before we understand them. We emphasize here, in support of the views on hierarchical models expressed in the 3 preceding papers by Draper, by Rogosa and Saner, and by de Leeuw and Kreft, the need to not diminish hard thinking about data and iterative model checking when fitting hierarchical models, the need for more and better software, the need to test methods to assure their proper calibration, and the need to produce supporting materials to aid analysts and users of hierarchical modeling methods.

Gender Differences in Secondary School Teachers' Control over Classroom and School Policy

The study described in this article examined the effect of school gender organization--whether it is a boys' school, girls' school, or coeducational school--on gender differences in teachers' perceptions of organizational control. The study was conducted in U. S. independent schools, both because of the variety of gender organization in these schools and because of the tendency for independent school teachers to have more organizational influence than their counterparts in public schools. Hierarchical linear modeling (HLM) methods were used to analyze a sample of 629 mathematics and English teachers in a stratified, nationally representative sample of 60 independent secondary schools. In coeducational schools and boys' schools, male teachers perceived greater influence over school policies outside of the classroom than did female teachers. These gender differences were especially great in coeducational schools. In girls' schools the trend was reversed, however, with female teachers experiencing greater influence than male teachers. These findings provide insight into school organizational factors, especially single-sex grouping, that either inhibit or facilitate the empowerment of women teachers.