The Effects of Score Group Width on the Mantel-Haenszel Procedure

Previous research examining the effects of reducing the number of score groups used in the matching criterion of the Mantel-Haenszel procedure, when screening for DIF, has produced ambiguous results. The goal of this study was to resolve the ambiguity by examining the problem with a simulated data set. The main results from this study call into question the preliminary recommendations of several other researchers that four or more score groups are sufficient and produce stable results. Although considerable stability and very little Type I error was noted with equal ability distribution comparisons, with unequal ability distributions, the Type I error rate was substantially inflated. These results argue against the appropriateness of implementing the procedure by collapsing score groups. The current data suggest that more than modest reductions in the number of score groups cannot be recommended when the ability distributions of the reference and focal groups differ     

Reforming Science Teaching: What Research Says About Inquiry

Journal of Science Teacher Education -     

Relationships between attitude and achievement among college biology students

The purposes of this study were to (1) study changes in attitude toward science, school, and academic self among college biology students, and (2) to examine relationships between attitudes and achievement in an introductory college course in biology. The three attitude variables were assessed at the beginning and end of the study. Each of the three constructs was measured by the semantic differential and one additional instrument. One cognitive measure, biology achievement, was taken at the beginning and end of the study. This was accomplished by using the Nelson Biology Test. Another cognitive measure, grade in the course, as given by the instructor, was recorded at the end of the course. Normative data and correlation coefficients among pre- and postadministrations were calculated for each institution and the composite sample as well. An analysis of variance showed that while gains in scores on the Nelson Biology Test were significant beyond the 0.01 level of probability, changes in attitude scores were not. Correlations were calculated between the attitude and cognitive variables in this study. Relationships between academic self-concept and achievement in biology were the strongest. Data from this study show that while student cognitive behavior was changed during an introductory college biology course, selected attitudes either stayed the same or became slightly more negative. Affective as well as cognitive gains would appear to be desirable goals in college courses. As we learn more about relationships that exist between cognition and affect, science educators at all levels will become better equipped to improve learning in science.     

The enterprise knowledge dictionary

One of the difficulties in knowledge management is that knowledge sources are widely distributed and exist in many forms. Earl's taxonomy (2001) of knowledge management systems, particularly, the Technocratic school – Systems, Cartographic, and Engineering, is described to provide a context for discussing the different types of knowledge management systems. To support these different types of knowledge sources, we describe an Enterprise Knowledge Dictionary (EKD) and the supporting n-tier architecture that allows access too many types of knowledge though a common interface. The EKD provides a knowledge portal that allows the knowledge seeker to locate and access the various types of knowledge for a domain of interest from a single source. In addition to facilitating knowledge reuse, the EKD is used for evaluation and planning of knowledge management activities within the firm. An n-tier architecture that both optimizes knowledge management implementations and minimizes the load on transaction processing systems is outlined.     

The UK/NL millimetre wave telescope

Astronomical observation in the millimetre wave region is of comparatively recent origin, but promises important contributions to our knowledge of the formation of stars, the structure of galaxies, and chemical reactions between ions and radicals not available in the laboratory. This article describes some of the very complex technological problems encountered in the design and construction of the important UK/NL millimetre wave telescope now nearing completion on the summit of Mauna Kea in Hawaii, and the kinds of result expected of it.     

The knowledge audit: Meta-Matrix analysis

Knowledge Management Research & Practice - Knowledge management is a method for simplifying and improving the process of sharing, distributing, creating, and understanding organizational...