Dams: Their Costs and Benefits

13 pages (includes illustrations). Contains 3 pages of references

Dams: Their Costs and Benefits

13 pages (includes illustrations). Contains 3 pages of references

An Environmental Perspective on Collaboration in Large Ecosystem Restoration Processes

13 pages (includes illustration). Contains 3 pages of references

It Takes at Least a Minute to Protect and Restore the Colorado River Delta [abstract]

2 pages

A Delta Once More: Restoring Riparian and Wetland Habitat in the Colorado River Delta

Outlines the delta's history and current political context, documents recent findings about the delta's partial recovery, and makes recommendations for maintaining existing flows to further benefit and sustain the remnant wetland ecosystems

AGU hydrology days 2005

2005 annual AGU hydrology days was held at Colorado State University on March 7 - March 9, 2005.Includes bibliographical references.The quality and reliability of hydrologic modes is a regular feature of surface water and groundwater disputes that make it to the courtroom. These models can be enormously useful, but at the same time are often suspect because of their complexity and their lack of transparency. N this paper I wish to visit the question of whether and how courts could approach the use of models, including the assessment of models and their results, before formal proceedings commence. My underlying assumption is that an improved assessment process can lead to better models, and ultimately, to fairer and more efficient outcomes. To do this, I review some of the literature on model building and testing, and some of the proposed guidelines on a number of the features of model construction and testing. I also look at two cases in which models played a central role, the Arkansas River Compact altercation (Kansas v. Colorado) and the Republican River Compact dispute (Kansas v. Nebraska and Colorado). They offer very different examples (if not extremes) of model building and use. Finally, I discuss some alternatives to cross examination of experts, once models are introduced

It Takes at Least a Minute to Protect and Restore the Colorado River Delta [abstract]

2 pages

Educational objectives and measurement of outcomes

Correlation and regression analysis are often used to infer causal relationships in dynamic systems, even though computed on cross-sectional static data. In education these analytic techniques have been used to support assertions that school-controlled variables make little contribution to student learning. Critics of these assertions point to the low quality of the data, but it may be that the techniques themselves are inappropriate for the development of inferences of causality. This study simulated four possible models of dynamic relationships between family and school inputs and achievement outcomes. The models were run for five periods. Data generated were submitted to correlation and regression analysis. Both unique variance and regression coefficient indicators failed to describe reliably causal relationships built into the models. Conclusion: complex systems resist simplistic analyses.