A Connection between Paired Data Analysis and Regression Analysis for Estimating Sales Adjustments

The two methods most often recommended for obtaining market-derived adjustments utilized in the sales comparison approach to appraisal are Paired Data Analysis and Multiple Regression Analysis. These approaches are viewed as competing alternatives, with advocates and detractors for each. The main purpose of this paper is to demonstrate that these two alternatives to estimating sales adjustments are equivalent under certain circumstances. This point of equivalence may prove to be a useful starting place for improving our understanding of the differences between and similarities of the two methods. After explaining the data requirements of each method, we provide a set of sufficient conditions under which the two methods produce identical adjustment estimates. We finish with a discussion ofrelative advantages and disadvantages of these two methods in estimating sale comparison adjustments.

Chemical dynamics

CHEMICAL EDUCATION is changing rapidly, not only because of the explosive growth of knowledge but also because the new knowledge has stimulated reformulation of working principles in the science. Undergraduate curricula and individual courses are in constant flux. Nowhere is the change and challenge greater than in freshman chemistry. Teachers of freshmen must meet the intellectual needs of students who have had more sophisticated and stimulating high school courses than those given a decade ago. At the same time, the freshman teacher must be aware of the constant modification of the more advanced courses in chemistry and other fields that his students will study later. Continuous reformulation of courses sometimes results in the inclusion of valuable new material at the expense of other equally valuable material. We believe that this has happened in some of the sophisticated courses in freshman chemistry. Structural chemistry often receives far greater emphasis than chemical dynamics. In 1965, the Westheimer Report (Chemistry: Opportunities and Needs, National Academy of Sciences, 1965) identified the three major fields of chemistry as structure, dynamics, and synthesis. We firmly believe that a balanced course in general chemistry should reflect the outlook of this report. The study of modern chemical synthesis is too demanding to be covered in depth in an introductory course. However, chemical dynamics -- the systematic study of reactions and reactivity -- can and should be studied at the freshman level. The study of changing chemical systems is the most fascinating part of the field for many students, and its early introduction forms a solid foundation for later study. This small volume is our attempt to answer the need. The book is intended for students who have had introductory stoichiometry, energetics, and structure at the level of a modern freshman textbook (for example, Basic Principles of Chemistry, by H. B. Gray and G. P. Haight, Jr., W. A. Benjamin, Inc., New York, 1961). Chemical Dynamics is designed to accompany approximately 20-25 lectures to be given as the concluding section of a freshman chemistry course. We have chosen topics for their fundamental importance in dynamics and then tried to develop a presentation suitable for freshman classes. Discussion of each topic is limited, because chemistry majors will inevitably return to all the subject matter in more advanced courses. We hope that the following ideas have been introduced with a firm conceptual basis and in enough detail for the student to apply them to chemical reality. 1. Thermodynamics and kinetics are two useful measures of reactivity. 2. Characteristic patterns of reactivity are systematically related to molecular geometry and electronic structure. 3. Reaction mechanisms are fascinating in their own right and indispensable for identification of significant problems in reaction rate theory. 4. The concepts underlying experiments with elementary reaction processes (molecular beams) are simple, even though the engineering of the experiments is complicated. 5. Application of theories of elementary reaction rates to most reactions (slow reactions, condensed media, etc.) provides enough challenge to satisfy the most ambitious young scientist. The book includes exercises at the end of each chapter except the last. Their purpose is didactic, inasmuch as most have been written with the aim of strengthening a particular point emphasized in the chapter, or of introducing an important topic which was not developed in the text for reasons of space and which would normally be taken up in greater detail in later courses. The material in this volume has been adapted primarily from a portion of the lectures given by H.B.G. and G.S.H. to the Chemistry 2 students at the California Institute of Technology during the academic years 1966-1967 and 1967-1968. These lectures were taped, written up by J.B.D., and distributed to the students in the form of class notes. The final manuscript was written after class-testing of the notes. Our decision to revise the Chemistry 2 notes in the form of an introductory text was made after H.B.G. and G.S.H. participated in the San Clemente Chemical Dynamics Conference, held in December 1966 under the sponsorship of the Advisory Council of College Chemistry. At San Clemente we found we were not the only group concerned over the exclusion of significant reference to chemical reactions and reactivity relationships in freshman courses. In addition to their general encouragement, which provided the necessary additional impetus, these colleagues prepared a series of papers for publication in an issue of the Journal of Chemical Education. It is a pleasure to acknowledge here the direct contribution these papers made in shaping the final form of our volume; specifically, in preparing Chapter 6, we have drawn examples from the San Clemente papers of Professors R. Marcus, A. Kuppermann and E. F. Greene, and J. Halpern. The concluding chapter of this book was developed from the lectures given by Professors E. F. Greene (dynamics in simple systems), Richard Wolfgang (atomic carbon), John D. Roberts (nuclear magnetic resonance), and F. C. Anson (electrochemical dynamics) to the students of Chemistry 2 in May 1967. These colleagues have kindly given us permission to use their material. We are grateful to Professors Ralph G. Pearson and Paul Haake, who read the entire manuscript and offered valuable criticism. It is a special pleasure to acknowledge the enormous contribution our students in Chemistry 2 made to the project. Their enthusiastic, critical attitude helped us make many improvements in the manuscript. Thanks are also due to four very special members of the staff of W. A. Benjamin, Inc., for seeing this project through with infectious vigor. Finally, and not the least, we acknowledge the role Susan Brittenham and Eileen McKoy played in preparing the final manuscript. JOSEPH B. DENCE HARRY B. GRAY GEORGE S. HAMMOND Pasadena, California January 196

Thirteen Unlikely Stories

Thirteen Unlikely Stories is a collection of fiction composed and revised at the University of Southern Mississippi’s Center for Writers

Farm Level Incidence of the U.S. Farm Policy Proposal to the WTO

A farm level simulation model is used to analyze the financial impacts of the U.S. proposal to the WTO to reduce farm subsidy payments. The impacts are examined for farms of different sizes, debt positions, and household characteristics. Results indicate that cash flow impacts of the policy change are much greater than net worth impacts.Agricultural and Food Policy,

Central Appalachian Understory Red Spruce (Picea rubens Sarg.) Growth Rates and Allometric Relationships

Red spruce (Picea rubens) was a prized timber species in West Virginia during the era of resource exploitation in the late 1800s and early 1900s. Consequently, Central Appalachian red spruce has faced large reductions in range and changes in stand composition. This region is relatively underrepresented in literature partially due to these constrictions. Investigating how stem growth occurs in young individuals can fill in some of our gaps in understanding the species and aid in restoration efforts. We sampled an array of high elevation sites on federal and state lands in West Virginia to analyze understory spruce growth and allometric relationships. We compared these relationships to those found in other regions in the range of red spruce. Stem analysis was carried out on understory trees. Results were applied to build reference curves to model growth percentiles for the young trees. Growth rates tend to peak between 10 and 30 years of age. Heights range from 0.95 m to 6.85 m after 50 years. Results allow for comparison of growth rates to the cohort of understory red spruce regionally. Nonlinear analysis was carried out on allometric measures on the same cohort of red spruce. Diameter at breast height was found to be a somewhat reliable predictor of total height as well as crown width. Total height was less reliable when predicting crown width. None of the three measures were found to be reliable for predicting tree age as may be expected with a shade tolerant species

Gaming in the Rio del Norte: Defining the Typology and Usage of Modified -Potsherds at Pot Creek Pueblo (LA 260, TA 1)

This report suggests that the majority of worked sherds recovered from Pot Creek Pueblo functioned as gaming pieces. A descriptive typology is designed to provide a qualitative framework from which probable usage designations are deduced. These usage designations are predicated on ethnographic and comparative archaeological data

Assessing Introductory Rural Sociology

This article reports on the results of an assessment of an introductory rural sociology course offered at two land-grant universities, which are very different in size. These institutions are North Carolina A&T State University and The Ohio State University. The authors use similar assessment tools, including an embedded pre and post test of knowledge gained, students’ written comments to open-ended questions administered at the end of term about the quality of the class and the instructors, and the traditional, standardized Student Evaluation of Instruction, an instrument used across many universities. In addition, at OSU, a small group diagnostic of students enrolled in introductory rural sociology was independently conducted by personnel from the university’s Center for the Advancement of Teaching. The results indicate that knowledge is gained, although post test results for some multiple choice questions were disappointing. Students’ written comments indicate that there was much about a sociological perspective applied to rural societies, communities, and peoples that they find interesting and about which they learned something. As well, students were uniformly positive about the way the courses were taught and graded. However, they were critical of the textbooks adopted by the instructors for both versions of the course, which they found inadequate because they were not rural-oriented in their content. The primary recommendation is for a follow-up assessment of various rural sociology courses and specific practices used by rural sociology instructors that include as many universities as possible, despite challenges this presents to development of a standardized methodology