Research papers

Effects of discovery and expository instructional methods on the attitude of students to biology

Gabriel Adeniyi Ajewole

Abstract The effects of discovery and expository instructional methods on the attitude of students to biology was investigated. The sample consisted of 240 Form IV biology students randomly drawn from six selected secondary schools in the Oyo state of Nigeria. They were assigned into two groups—experimental and control. The experimental group was exposed to the discovery method, and the control group was taught using the expository method. The science class of Form IV in each of the six schools was selected intact for the study. A nonrandomized pretest‐posttest control group design was employed. The major instrument was the 40–item Scientific Attitude Questionnaire (SAQ). It is a Likert‐type questionnaire using five scales. Two hypotheses were tested. Analyses of the results showed that the experimental group evinced a significantly more favorable attitude to biology than the control group (t = 8.87, p < 0.01). It was also found that the high, average‐, and low‐ability groups in the experimental class evinced a more favorable attitude to biology than their counterparts in the control class. However, there was no significant difference in the attitude of male and female students exposed to the discovery and expository methods (F1,227 = 0.07, p > 0.999). The article concludes with a recommendation that science learning using the discovery method may enable the learner to evince more a favorable attitude toward problem recognition and problem solving than when learning is done by the expository method.

Department of Computer Science

Marco de Gemmis, Ernesto William, De Luca, Tommaso Di Noia, Aldo Gangemi, Michael Hausenblas, Pasquale Lops, Thomas Lukasiew…

Firm Resources and Sustained Competitive Advantage

Jay B. Barney

Understanding sources of sustained competitive advantage has become a major area of research in strategic management. Building on the assumptions that strategic resources are heterogeneously distributed acrossfirms and that these differences are stable over time, this article examines the link betweenfirm resources and sustained competitive advantage. Four empirical indicators of the potential of firm resources to generate sustained competitive advantage-value, rareness, imitability, and substitutability-are discussed. The model is applied by analyzing the potential of severalfirm resourcesfor generating sustained competitive advantages. The article concludes by examining implications of this firm resource model of sustained competitive advantage for other business disciplines.

Case Study Research: Design and Methods

Harris Chaiklin

Object oriented modeling and design

James Rumbaugh, Michael Blaha, William Premerlani, Frederick D. Eddy, William E. Lorensen

1. Introduction. I. MODELING CONCEPTS. 2. Modeling as a Design Technique. 3. Object Modeling. 4. Advanced Object Modeling. 5. Dynamic Modeling. 6. Functional Modeling. II. DESIGN METHODOLOGY. 7. Methodology Preview. 8. Analysis. 9. System Design. 10. Object Design. 11. Methodology Summary. 12. Comparison of Methodologies. III. IMPLEMENTATION. 13. From Design to Implementation. 14. Programming Style. 15. Object-Oriented Languages. 16. Non-Object-Oriented Languages. 17. Databases. 18. Object Diagram Compiler. 19. Computer Animation. 20. Electrical Distribution Design System. 21. Future of Object-Oriented Technology. Appendix A: OMT Graphical Notation. Appendix B: Glossary. Index.

Free radicals in biology and medicine

J. M. C. Gutteridge

Handbook of theoretical computer science

Jan Van Leeuwen

Of all the books I have covered in the Forum to date, this set is the most unique and possibly the most useful to the community, in support both of teaching and research.... The books can be used by anyone wanting simply to gain an understanding of one of these areas, or by someone desiring to be in research in a topic, or by instructors wishing to find timely information on a subject they are teaching outside their major areas of expertise. -- Rocky Ross, SIGACT News This is a reference which has a place in every computer science library. -- Raymond Lauzzana, Languages of Design The Handbook of Theoretical Computer Science provides professionals and students with a comprehensive overview of the main results and developments in this rapidly evolving field. Volume A covers models of computation, complexity theory, data structures, and efficient computation in many recognized subdisciplines of theoretical computer science. Volume B takes up the theory of automata and rewriting systems, the foundations of modern programming languages, and logics for program specification and verification, and presents several studies on the theoretic modeling of advanced information processing. The two volumes contain thirty-seven chapters, with extensive chapter references and individual tables of contents for each chapter. There are 5,387 entry subject indexes that include notational symbols, and a list of contributors and affiliations in each volume.

EuroQol - a new facility for the measurement of health-related quality of life

The EuroQol Group

The effect of concept mapping on students' anxiety and achievement in biology

Olugbemiro J. Jegede, Folusho F. Alaiyemola, Peter Akinsola Okebukola

Abstract The results of recent studies into the use of the concept mapping heuristic seem to demonstrate that meaningful learning results through its use in science classrooms. While this underscores the need to use more effective instructional strategies in science teaching, the issue of the intervening variable of anxiety in learning and science achievement, and the possible use of a metacognitive strategy in anxiety reduction have not been addressed. This study, therefore, sought to find out if the metacognitive strategy of concept mapping reduces anxiety and thereby enhances achievement in biology. A total of 51 (30 boys, 21 girls) senior secondary one (grade 10) students participated in this experiment. Two instruments—the Zuckerman Affect Adjective Checklist and the Biology Achievement Test—were used in pre‐ and posttest administrations to measure the treatment effect on anxiety and achievement, respectively. Findings support the stand that concept mapping is significantly more effective than the traditional/expository teaching strategy in enhancing learning in biology. In addition, it apparently reduces students' anxiety towards the learning of biology. A significant reduction of anxiety was noticed for male subjects.

Institutions, Institutional Change and Economic Performance

Douglass C. North

Continuing his groundbreaking analysis of economic structures, Douglass North develops an analytical framework for explaining the ways in which institutions and institutional change affect the performance of economies, both at a given time and over time. Institutions exist, he argues, due to the uncertainties involved in human interaction; they are the constraints devised to structure that interaction. Yet, institutions vary widely in their consequences for economic performance; some economies develop institutions that produce growth and development, while others develop institutions that produce stagnation. North first explores the nature of institutions and explains the role of transaction and production costs in their development. The second part of the book deals with institutional change. Institutions create the incentive structure in an economy, and organisations will be created to take advantage of the opportunities provided within a given institutional framework. North argues that the kinds of skills and knowledge fostered by the structure of an economy will shape the direction of change and gradually alter the institutional framework. He then explains how institutional development may lead to a path-dependent pattern of development. In the final part of the book, North explains the implications of this analysis for economic theory and economic history. He indicates how institutional analysis must be incorporated into neo-classical theory and explores the potential for the construction of a dynamic theory of long-term economic change. Douglass C. North is Director of the Center of Political Economy and Professor of Economics and History at Washington University in St. Louis. He is a past president of the Economic History Association and Western Economics Association and a Fellow, American Academy of Arts and Sciences. He has written over sixty articles for a variety of journals and is the author of The Rise of the Western World: A New Economic History (CUP, 1973, with R.P. Thomas) and Structure and Change in Economic History (Norton, 1981). Professor North is included in Great Economists Since Keynes edited by M. Blaug (CUP, 1988 paperback ed.)

Basic local alignment search tool

Stephen F. Altschul, Warren Gish, Webb Miller, Eugene W. Myers, David J. Lipman

Government Spending in a Simple Model of Endogeneous Growth

Robert J. Barro

One strand of endogenous-growth models assumes constant returns to a broad concept of capital. I extend these models to include tax- financed government services that affect production or utility. Growth and saving rates fall with an increase in utility-type expenditures; the two rates rise initially with productive government expenditures but subsequently decline. With an income tax, the decentralized choices of growth and saving are "too low," but if the production function is Cobb-Douglas, the optimizing government still satisfies a natural condition for productive efficiency. Empirical evidence across countries supports some of the hypotheses about government and growth.

A new method which gives an objective measure of colonization of roots by vesicular—arbuscular mycorrhizal fungi

Terence P. McGonigle, M. H. Miller, D. G. Evans, G. Fairchild, J. Swan

Previously described methods to quantify the proportion of root length colonized by vesicular-arbuscular (VA) mycorrhizal fungi are reviewed. It is argued that these methods give observer-dependent measures of colonization which cannot be used to compare, quantitatively, roots examined by different researchers. A modified method is described here to estimate VA mycorrhizal colonization on an objective scale of measurement, involving inspection of intersections between the microscope eyepiece crosshair and roots at magnification × 200; it is referred to as the magnified intersections method. Whether the vertical eyepiece crosshair crosses one or more arbuscules is noted at each intersection. The estimate of colonization is the proportion of root length containing arbuscules, called the arbuscular colonization (AC). The magnified intersections method also determines the proportion of root length containing vesicles, the vesicular colonization (VC), and the proportion of root length containing hyphae, the hyphal colonization (HC). However, VC and HC should be interpreted with caution because vesicles and hyphae, unlike arbuscules, can be produced in roots by non-mycorrhizal fungi.

A genetic model for colorectal tumorigenesis

Eric R. Fearon, Bert Vogelstein

Molecular cloning: A laboratory manual

Prescott L. Deininger

Comparative Biology of two Phycitid Moths, Plodia Interpunctella (Hubn.) and Ephestia Cautella (WLK.) on some Selected Food Media

J. Allotey, Linee Goswami

Microwave Engineering

David M. Pozar

The 4th edition of this classic text provides a thorough coverage of RF and microwave engineering concepts, starting from fundamental principles of electrical engineering, with applications to microwave circuits and devices of practical importance. Coverage includes microwave network analysis, impedance matching, directional couplers and hybrids, microwave filters, ferrite devices, noise, nonlinear effects, and the design of microwave oscillators, amplifiers, and mixers. Material on microwave and RF systems includes wireless communications, radar, radiometry, and radiation hazards. A large

Absorptive Capacity: A New Perspective on Learning and Innovation

Wesley M. Cohen, Daniel A. Levinthal

Wesley M. Cohen, Daniel A. Levinthal, Absorptive Capacity: A New Perspective on Learning and Innovation, Administrative Science Quarterly, Vol. 35, No. 1, Special Issue: Technology, Organizations, and Innovation (Mar., 1990), pp. 128-152

A Model of Distributor Firm and Manufacturer Firm Working Partnerships

James C. Anderson, James A. Narus

A model of distributor firm and manufacturer firm working partnerships is presented and is assessed empirically on a sample of distributor firms and a sample of manufacturer firms. A multiple-informant research method is employed. Support is found for a number of the hypothesized construct relations and, in both manufacturer firm and distributor firm models, for the respecification of cooperation as an antecedent rather than a consequence of trust. Some implications for marketing practice are discussed briefly.

Personality Structure: Emergence of the Five-Factor Model

John M. Digman

There is clear evidence that parents can and do influence children. There is equally clear evidence that children’s genetic makeup affects their own behavioral characteristics, and also influences the way they are treated by their parents. Twin and ...Read More

Comparative fit indexes in structural models.

Peter M. Bentler

Normed and nonnormed fit indexes are frequently used as adjuncts to chi-square statistics for evaluating the fit of a structural model. A drawback of existing indexes is that they estimate no known population parameters. A new coefficient is proposed to summarize the relative reduction in the noncentrality parameters of two nested models. Two estimators of the coefficient yield new normed (CFI) and nonnormed (FI) fit indexes. CFI avoids the underestimation of fit often noted in small samples for Bentler and Bonett's (1980) normed fit index (NFI). FI is a linear function of Bentler and Bonett's non-normed fit index (NNFI) that avoids the extreme underestimation and overestimation often found in NNFI. Asymptotically, CFI, FI, NFI, and a new index developed by Bollen are equivalent measures of comparative fit, whereas NNFI measures relative fit by comparing noncentrality per degree of freedom. All of the indexes are generalized to permit use of Wald and Lagrange multiplier statistics. An example illustrates the behavior of these indexes under conditions of correct specification and misspecification. The new fit indexes perform very well at all sample sizes.

Free Radicals in Biology and Medicine

E.T. Land

(1990). Free Radicals in Biology and Medicine. International Journal of Radiation Biology: Vol. 58, No. 4, pp. 725-725.

How to Design and Evaluate Research in Education

Jack R. Fraenkel, Norman E. Wallen

Part One: Introduction to Research Chapter 1: The Nature of Educational Research Part Two: The Basics of Educational Research Chapter 2: The Research Problem Chapter 3: Ethics and Research Chapter 4: Variables and Hypotheses Chapter 5: Reviewing the Literature Chapter 6: Sampling Chapter 7: Instrumentation Chapter 8: Validity and Reliability Chapter 9: Internal Validity Part Three: Data Analysis Chapter 10: Descriptive Statistics Chapter 11: Inferential Statistics Chapter 12: Statistics in Perspective Part Four: Research Methodologies: I Chapter 13: Experimental Research Chapter 14: Single-Subject Research Chapter 15: Correlational Research Chapter 16: Causal-Comparative Research Chapter 17: Survey Research Part Five: Research Methodologies: II Chapter 18: Content Analysis Research Chapter 19: Qualitative Research: I Chapter 20: Qualitative Research: II Chapter 21: Historical Research Part Six: Preparing Research Proposals and Reports Chapter 22: Writing Research Proposals and Reports Part Seven: Research by Practitioners Chapter 23: Doing Research in Schools Appendix A: Table of Random Numbers Appendix B: Normal Curve Table Appendix C: Chi-Square Distribution Appendix D: Illustration of Statistical Procedures

Strategies for theory construction nursing

CB Hough