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- Genre: Academic theses
- Status: Published
Description
Random Forests is a statistical learning method which has been proposed for propensity score estimation models that involve complex interactions, nonlinear relationships, or both of the covariates. In this dissertation I conducted a simulation study to examine the effects of three Random Forests model specifications in propensity score analysis. The results suggested that, depending on the nature of data, optimal specification of (1) decision rules to select the covariate and its split value in a Classification Tree, (2) the number of covariates randomly sampled for selection, and (3) methods of estimating Random Forests propensity scores could potentially produce an unbiased average treatment effect estimate after propensity scores weighting by the odds adjustment. Compared to the logistic regression estimation model using the true propensity score model, Random Forests had an additional advantage in producing unbiased estimated standard error and correct statistical inference of the average treatment effect. The relationship between the balance on the covariates' means and the bias of average treatment effect estimate was examined both within and between conditions of the simulation. Within conditions, across repeated samples there was no noticeable correlation between the covariates' mean differences and the magnitude of bias of average treatment effect estimate for the covariates that were imbalanced before adjustment. Between conditions, small mean differences of covariates after propensity score adjustment were not sensitive enough to identify the optimal Random Forests model specification for propensity score analysis.
ContributorsCham, Hei Ning (Author) / Tein, Jenn-Yun (Thesis advisor) / Enders, Stephen G (Thesis advisor) / Enders, Craig K. (Committee member) / Mackinnon, David P (Committee member) / Arizona State University (Publisher)
Created2013
Description
Owner organizations in the architecture, engineering, and construction (AEC) industry are presented with a wide variety of project delivery approaches. Implementation of these approaches, while enticing due to their potential to save money, reduce schedule delays, or improve quality, is extremely difficult to accomplish and requires a concerted change management effort. Research in the field of organizational behavior cautions that perhaps more than half of all organizational change efforts fail to accomplish their intended objectives. This study utilizes an action research approach to analyze change message delivery within owner organizations, model owner project team readiness and adoption of change, and identify the most frequently encountered types of resistance from lead project members. The analysis methodology included Spearman's rank order correlation, variable selection testing via three methods of hierarchical linear regression, relative weight analysis, and one-way ANOVA. Key findings from this study include recommendations for communicating the change message within owner organizations, empirical validation of critical predictors for change readiness and change adoption among project teams, and identification of the most frequently encountered resistive behaviors within change implementation in the AEC industry. A key contribution of this research is the recommendation of change management strategies for use by change practitioners.
ContributorsLines, Brian (Author) / Sullivan, Kenneth (Thesis advisor) / Wiezel, Avi (Committee member) / Badger, William (Committee member) / Arizona State University (Publisher)
Created2014
Description
The construction industry is performing poorly regarding project management and service delivery. On average, global projects are over-budget, delayed, and met with unsatisfactory results according to buyers. To mitigate poor performance, the project management career path has been heavily researched and continually developed over the last century. Despite the published advances in project management approaches and tools, project performance continues to suffer. This research seeks to conduct an exploratory analysis of current project management and other approaches and determine how they affect project performance. Through a detailed literature search, the researcher identified a procurement model that is more heavily documented as high performing than all other approaches. The researcher proposed that this model may be a solution to assist project managers with the delivery of high performing services. The model is called the Best Value Approach (BVA). The BVA focuses on leadership, non-technical communication, quality assurance, and transparent project execution. To test the effectiveness of its practices, the researcher modified and adapted the BVA into a project management approach and tested it on a large-scale government project. During the case study test, the researcher observed that there were two primary project management roles in the supply chain; the buyer’s and vendor’s project managers. The case study resulted in the large government organization receiving more work and increased their satisfaction of the work received by 22 percent from the previous year. To further test the project management adapted BVA, the researcher conducted a classroom case-study in which students learned and implemented the BVA practices on real-time, small-scale industry projects. Results include cost savings of $100,000 for 10 companies over 24 projects, cost avoidance of over $4.5M, and a 9.8/10 customer satisfaction [in terms of the companies’ satisfaction with the deliverables produced on each project]. These results suggest that the BVA practices may effectively improve the performance of project delivery, and may be a viable new project management approach to train future project managers. Out of the two project manager roles, it is proposed that the buyer’s project manager may receive the most benefit. Additional research is needed on the other approaches to compare quantitative project performance, and run repeated testing on the potential new project management approach.
ContributorsRivera, Alfredo Octavio (Author) / Badger, William (Thesis advisor) / Sullivan, Kenneth (Thesis advisor) / Kashiwagi, Jacob S (Committee member) / Arizona State University (Publisher)
Created2017
Description
The discipline of continuing professional development (CPD) is well defined and established within a variety of industries, such as medical, legal, and financial. The built environment is a less defined and mature industry with respect to educational pathways and professional education, with no uniform structure. Occupational licensing, such as registered nurses, certified professional accountants, and others are well known within both their industries and the public. Additionally, occupational core-competencies are well established. Planning is a core skill set within the built environment and construction management. Definitions of the term “planning” vary quite broadly across the built environment, but generally includes activities such as risk identification, scope identification, and scheduling. Understanding how professionals in the built environment learn to plan is critical to meeting CPD needs for planning skills and the ability of a professional to “plan” effectively. Many planning tools and software have been developed, but often rely on an individual professional’s personal experiences and abilities. Limited literature in the field of professional education in the built environment has left a gap on the topic of how to train professionals in planning competencies. Survey results indicate that current training is not meeting the expectations of professionals, as only 16 percent of professionals are trained how to plan using their preferred method of learning. While on-the-job training is the primary format, the most preferred format is internal company training, but only 54 percent of companies provide this format. Mann-Whitney U and Kruskal Wallis tests were conducted and revealed that organizations with internal training programs have higher employee satisfaction with their organization’s planning process. Further, organizations with internal training programs are seen as having a more formal internal planning process. Research is needed to develop CPD within construction management and provide the foundation upon which a professional education structure can be created. An andragogically-centered schema for a heuristic approach to construction CPD is developed and tested on a seminar for pre-project planning. The full instructional design of the seminar using the model is disclosed and seminar results showed positive results and participants achieved high levels of learning.
ContributorsHurtado, Kristen (Author) / Sullivan, Kenneth (Thesis advisor) / Wiezel, Avi (Committee member) / Badger, William (Committee member) / Arizona State University (Publisher)
Created2018
Description
Construction Management research has not been successful in changing the practices of the construction industry. The method of receiving grants and the peer review paper system that academics rely on to achieve promotion, does not align to academic researchers becoming experts who can bring change to industry practices. Poor construction industry performance has been documented for the past 25 years in the international construction management field. However, after 25 years of billions of dollars of research investment, the solution remains elusive. Research has shown that very few researchers have a hypothesis, run cycles of research tests in the industry, and result in changing industry practices.
The most impactful research identified in this thesis, has led to conclusions that pre-planning is critical, hiring contractors who have expertise will result in better performance, and risk is mitigated when the supply chain partners work together and expertise is utilized at the beginning of projects.
The problems with construction non-performance have persisted. Legal contract issues have become more important. Traditional research approaches have not identified the severity and the source of construction non-performance. The problem seems to be as complex as ever. The construction industry practices and the academic research community remain in silos. This research proposes that the problem may be in the traditional construction management research structure and methodology. The research
has identified a unique non-traditional research program that has documented over 1700 industry tests, which has resulted in a decrease in client management by up to 79%, contractors adding value by up to 38%, increased customer satisfaction by up to 140%, reduced change order rates as low as -0.6%, and decreased cost of services by up to 31%.
The purpose of this thesis is to document the performance of the non-traditional research program around the above identified results. The documentation of such an effort will shed more light on what is required for a sustainable, industry impacting, and academic expert based research program.
The most impactful research identified in this thesis, has led to conclusions that pre-planning is critical, hiring contractors who have expertise will result in better performance, and risk is mitigated when the supply chain partners work together and expertise is utilized at the beginning of projects.
The problems with construction non-performance have persisted. Legal contract issues have become more important. Traditional research approaches have not identified the severity and the source of construction non-performance. The problem seems to be as complex as ever. The construction industry practices and the academic research community remain in silos. This research proposes that the problem may be in the traditional construction management research structure and methodology. The research
has identified a unique non-traditional research program that has documented over 1700 industry tests, which has resulted in a decrease in client management by up to 79%, contractors adding value by up to 38%, increased customer satisfaction by up to 140%, reduced change order rates as low as -0.6%, and decreased cost of services by up to 31%.
The purpose of this thesis is to document the performance of the non-traditional research program around the above identified results. The documentation of such an effort will shed more light on what is required for a sustainable, industry impacting, and academic expert based research program.
ContributorsRivera, Alfredo O (Author) / Kashiwagi, Dean T. (Thesis advisor) / Sullivan, Kenneth (Committee member) / Kashiwagi, Jacob S (Committee member) / Arizona State University (Publisher)
Created2014