The empirical testing of theories is an important component of research in any field. Yet despite the long history of science, the extent to which theories are supported or contradicted by the results of empirical research remains ill defined. Quite commonly, support or contradiction is based solely on the "reject" or "fail to reject" decisions that result from tests of null hypotheses that are derived from aspects of theory. Decisions and recommendations based on this forced and often artificial dichotomy have been scrutinized in the past. In recent years, such an overly simplified approach to theory testing has been vigorously challenged in the past.Theories differ in the extent to which they provide precise predictions about observations. The precision of predictions derived from theories is proportional to the strength of support that may be provided by empirical evidence congruent with the prediction. However, the notion of precision linked to strength of support is surprisingly absent from many discussions regarding the appraisal of theories. Meehl (1990a) has presented a logically sound index of corroboration to summarize the extent to which empirical tests of theories provide support or contradiction of theories. The purpose of this study was to evaluate the utility of this index of corroboration and its behavior when employing path analytic methods in the context of social science research. The performance of a multivariate extension of Meehl’s Corroboration Index (Ci) was evaluated using Monte Carlo methods. Correlational data were simulated to correspond to tests of theories via traditional path analysis. Five factors were included in the study: number of variables in the path model, level of intolerance of the theory, correspondence of the theory to the ‘true’ path model used for data generation, sample size and level of collinearity. Results were evaluated in terms of the mean and standard error of the resulting multivariate Ci values. The level of intolerance was observed to be the strongest influence on mean Ci. Verisimilitude and model complexity were not observed to be strong determinants of the mean Ci. Sample size and collinearity evidenced small relationships with the mean value of Ci, but were more closely related to the sampling error. Implications for theory and practice include alternatives and complements to tests of statistical significance, a shift from comparing findings to the null hypothesis, to the comparison of alternative theories and models, and the inclusion of additional logical components besides the theory itself. Lastly, an alternative conceptualization of the multivariate corroboration index is advanced to guide future research efforts.

The concept of function is one of the essential topics in the teaching and learning of secondary mathematics because of the central and unifying role it plays within secondary and college level mathematics. Organizations, such as the National Council of Teachers of Mathematics, suggest students should be able to make connections across multiple representations of mathematical functions by the time they complete high school. Despite the prominent role functions play in secondary mathematics curriculum, students continue to struggle with the complex notion of functions and especially have difficulty using the different representations that are inherent to functions (algebraic, graphical and tabular). Technology is often considered an effective tool in raising student achievement, especially in learning functions where the different representations of a graphing calculator are analogous to the different representations of a function. Opportunity to learn is another important consideration when examining achievement and is generally considered one of, if not the most important, factor in student achievement. Opportunity to learn, or the measure of to what extent students have had an opportunity to learn or review a concept, is often measured with self-reports of content coverage. This study examined the relationship between opportunity to learn, students'; use of graphing calculators, and achievement within a curriculum that supports integrated use of technology and focuses on conceptual understanding of mathematical concepts. The research questions focused on what opportunities students had to learn functions from the enacted curriculum, what calculator strategies students used when solving function problems, how both opportunity to learn and calculator strategies influenced student achievement, and what relationships exist between opportunity to learn, use of calculator strategies, and student achievement. This study is an in-depth secondary analysis of a portion of data collected as part of the evaluation study of Precalculus and Discrete Mathematics (Third Edition, Field-Trial Version) developed by the University of Chicago School Mathematics Project. Participants in this study (n = 271) came from six schools, seven teachers, and 14 classes. Instruments in this study include two pretests (one with technology and one without) and three posttests (two with technology and one without) and a calculator usage survey for one posttest. In addition to five student assessments, teachers completed opportunity-to-learn surveys for the posttests and chapter evaluations forms on which they indicated the lessons taught and the homework problems assigned from the textbook. Some students (n = 151) had access to graphing calculators equipped with computer algebra systems (CAS) while others (n = 120) had access to graphing calculators. Students had multiple opportunities to learn functions as measured by lessons taught, homework assigned, and posttest items teachers reported as having taught or reviewed the content necessary for students to correctly answer the items. Overall, students showed a positive increase in achievement between the pretests and posttests. In general, achievement was positively correlated to OTL Lessons, negatively correlated to OTL Homework, and had no correlation to OTL Posttests when controlling for prior knowledge. Results indicate students appear to be, for the most part, making wise choices about when and how to use graphing calculators to solve function items. Students prefer the graphical representation and are rarely using CAS features or tables, even when they are the best choices for solving a problem. Results from hierarchical linear models (HLM) show use of strategies (beta = 0.96), access to CAS (beta = 5.12), and OTL lessons (beta = 0.75) all had significant and positive impacts on student achievement for one of the posttests, when controlling for prior knowledge. Results from path analyses also indicated use of strategies had a direct and positive effect (beta =0 .14) on student achievement but showed access to CAS had a negative indirect effect (beta = -0.64) on student achievement for the same posttest mitigated through OTL Lessons (beta = 0.30). The results of this study have implications for both researchers and mathematics educators who seek to understand ways in which teachers can increase students'; understanding of functions and student achievement. The relationship between the use of technology and student achievement in relation to opportunity to learn is complex, but use of calculator strategies appears to have a positive effect on students' opportunity to learn functions and student achievement when used in a curriculum that focuses on conceptual understanding and integrates technology.

Compulsive hoarding is characterized by difficulty discarding unneeded items and the accumulation of items within living spaces and is associated with significant functional impairment and distress. Along with the negative impact on the individual, previous reports have indicated that compulsive hoarding is not only impairing and substantially burdensome for family members, but also linked to disruptions in family functioning. The present study utilized a path model analysis to examine the associations between an array of hoarding variables hypothesized to impact family functioning and parent-adult child relationships in 199 adult children of hoarders. Results revealed that family functioning mediated the relationship between hoarding severity and parent-adult child relationship. Decreased insight into hoarding symptoms was directly associated with decreased quality of parent-adult child relationships, which was mediated by family functioning. Increased family accommodation was significantly associated with increased impairment (work, social, family domains) in adult children of hoarders. Clinical implications and future directions in research are discussed.

This study is concerned with the problem of resource-constrained project scheduling which includes splittable and nonsplittable jobs, renewable and nonrenewable resources, variation in resource availabi1ity, time-resource tradeoff, time-cost tradeoff, and multiple objectives. The problem is formulated as a zero-one integer programming model. A specialized solution technique is developed for the preemptive goal programming, resource-constrained project. scheduling problem for time, cost, and resource leveling objectives. In addition, single objective algorithms are also provided for the time, cost, and resource leveling objectives. These algorithms are based on the idea of the implicit enumeration process, and use the special structures of the problem to expedite the search process. Computer-generated problems are used to test each of the single objective algorithms. The results show that the algorithms give optimal solutions to tested problems with time and cost objectives using a reasonable computation time; however, heuristic solutions are more feasible for problems with resource leveling objective. The multiple objective algorithm is illustrated through application to a warehouse project problem. / Graduation date: 1993

The purpose of this study was to examine general life stressors and emotion-focused and problem-focused coping strategies as prospective predictors of psychological distress in a sample of 209, low-income, urban, HIV-positive, African-American women. A secondary aim was to determine whether coping strategies mediated the relationship between life stressors and psychological distress. This study involved a secondary data analysis from a longitudinal National Institutes of Health (NIH) funded, randomized, family therapy efficacy study (Structural Ecosystems Therapy [SET]; Szapocznik et al., 2004). Participants completed self-report measures, including the Brief Symptom Inventory, Brief Cope (adapted), and Difficult Life Circumstances, as measures of psychological distress, problem-focused and emotion-focused coping, and general life stressors, respectively. These measures were completed at baseline, and at 3, 6, 9, and 18-month follow-up assessments. Results from longitudinal, cross-lagged, path model analyses provided some modest support regarding the hypothesis relating amount of life stressors to subsequent level of psychological distress symptoms. Results of the coping path models failed to support the hypotheses relating problem-focused coping and emotion-focused coping to subsequent distress (Hypotheses 2 and 3). Furthermore, the lack of direct associations between coping strategies and distress prohibited the examination of problem-focused and emotion-focused coping strategies as possible mediators in the relationship between life stressors and psychological distress. Results and implications are discussed.

<p>Diss. Umeå : Universitet, 1985</p> / digitalisering@umu

Between 1988 and 1989, an intensive archaeological survey of a small drainage known as Roan Mare coulee in southern Saskatchewan was conducted by Dr. Ernest Walker (Walker 1990). Among the 120 archaeological sites in the area, seven bison kills and a vast array of associated drivelines were identified. This study focuses upon the spatial interaction amongst the kills, the drivelines and the local environment in relation to the bison hunting strategies used on the Northern Plains. This is done by modelling where bison are likely to move in the terrain as well as how the topography obstructs their line of sight. As this problem covers a large spatial area and multiple different data sources, Geographic Information Systems (GIS) are integrated into the research design in the form of Least Cost Path and Viewshed analyses. Both archaeological data from Walker's survey and environmental data such as elevation and water sources served as the input datasets required by ArcGIS's spatial analysis tools. The results of the Least Cost Path analyses were compared visually to both the location and orientation of the driveline evidence, while the viewshed results were compared to the trap's location at the valley edge. The results of this research showed that the drivelines found at Roan Mare coulee appear to be following the general orientation of the landscape at the broadest scales, and likely served to funnel bison over large distances. There also appear to be several locations on the landscape that are amenable to moving bison to several different sites. The viewshed evidence shows the smaller scale nuances between bison vision and the terrain in a hypothetical drive event. The differences in the viewable area available to the bison at each site likely played a role in the chosen strategy employed when that site was used. It is hoped that this style of research can be continued with higher quality data and additional variables to help clarify many of the subtleties found in a Plains bison drive.

In the process of urbanization, the population and economy are rapidly growing. To achieve the demand of urbanization, natural areas are developed into construction areas in the city. Nature areas began to shrink and fragment, causing a great deal of damage, such as species extinction. The ability of nature to control the flood, adjust the rain, and filter pollution has been lost. This study is based on the city of Kaohsiung and Kaohsiung County. The study uses a large scale to re-examine the spatial structure of this area to propose an effective and reasonable planning policy for the environment and ecosystem. The study introduces the concept of green infrastructure to develop a green network system for the city. Green infrastructure is a network connecting natural areas and open spaces that can save ecological value and retain the ecosystem function. A green infrastructure network consists of hubs and links, and the network pattern can be made for different purposes. The study chose green land with an area of more than twenty hectares for the hubs and chose the terrestrial animal for the target species. The study uses the least-cost path analysis to plan the links for the terrestrial animal. The least-cost path, which is the path of least resistance when the terrestrial animal passes through the landscape. All the hubs generated 903 links. To create the green infrastructure networks, this study uses the gravity model to evaluate which corridor is the most important. Using the graph theory, the study developed three plans for a green infrastructure network to meet different demands: the Paul Revere, Traveling Salesman, and Least Cost to User networks. Planners can see different demands dictating the choice between different green infrastructure networks. Finally, the study discusses the three-network structure, finding the important hubs and links for the terrestrial animal. These areas should be protected to maintain the green infrastructure network.

The purpose of the study was to assess 5th grade Turkish students&rsquo / environmental literacy (EL) level by considering six EL components, and explore the factors predicting the environmentally responsible behaviors (ERB) of these students. The research design of the study was nation-wide survey. The sample of the survey consisted of 2412 fifth grade students selected from 78 elementary schools (26 private and 52 public) in 26 provinces across Turkey. Developed by the researcher, Elementary School Environmental Literacy Instrument (ESELI) including five parts and total 81 items was used as data collection instrument. To analyze quantitative data, descriptive statistics, ANOVA, multiple correlation and path analysis were conducted. The responses to open-ended question were subjected to content analysis. The results of the study revealed that EL score of the students was found 149 (SD=26.19) suggesting moderate level of EL and 64.1% of the students (n=1545) had moderate level EL. The factors significantly affecting 5th grade students&rsquo / ERB and the effect size of these factors were as follows / school type (partial =.007), taking pre-school education (partial =.002), mother education level (partial =.007), father education level (partial =.012), residence (partial =.008), experiences in the natural regions (partial =.046), curiosity toward environmental information (partial =.048), mother environmental concern (partial =.023), father environmental concern (partial =.031) and sibling environmental concern (partial =.014). Furthermore, a combination of environmental knowledge, willingness to take environmental action, cognitive skills, and environmental attitude and environmental sensitivity explained 12% of the variance in ERB. As a conclusion, the results of the presents study will shed light on the attempts on policy making and curriculum development regarding environmental education.

Includes vita. / Title from PDF of title page. / Document formatted into pages; contains 158 pages. / Thesis (Ph.D.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The empirical testing of theories is an important component of research in any field. Yet despite the long history of science, the extent to which theories are supported or contradicted by the results of empirical research remains ill defined. Quite commonly, support or contradiction is based solely on the "reject" or "fail to reject" decisions that result from tests of null hypotheses that are derived from aspects of theory. Decisions and recommendations based on this forced and often artificial dichotomy have been scrutinized in the past. Such an overly simplified approach to theory testing has been vigorously challenged in the past. Theories differ in the extent to which they provide precise predictions about observations. The precision of predictions derived from theories is proportional to the strength of support that may be provided by empirical evidence congruent with the prediction. / ABSTRACT: However, the notion of precision linked to strength of support is surprisingly absent from many discussions regarding the appraisal of theories. In the early 1990s, Meehl presented an index of corroboration to summarize the extent to which empirical tests of theories provide support or contradiction of theories. This index is comprised of a closeness component and an estimate of precision. The purpose of this study was to evaluate the utility of this index of corroboration and its behavior when employing path analytic methods in the context of social science research. The performance of a multivariate extension of Meehl's Corroboration Index (Ci) was evaluated using Monte Carlo methods by simulating traditional path analysis. Five factors were included in the study: model complexity, level of intolerance, verisimilitude, sample size and level of collinearity. Results were evaluated in terms of the mean and standard error of the resulting multivariate Ci values. / ABSTRACT: Of the five central design factors investigated, the level of intolerance was observed to be the strongest influence on mean Ci. Verisimilitude and model complexity were not observed to be strong determinants of the mean Ci. The lack of sensitivity of the index to the other design factors led to a proposed alternative conceptualization of the multivariate corroboration index to guide future research efforts. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.