Preformal proving: Examples and reflections

The starting point of our reflections is a classroom situation in grade 12 in which it was to be proved intuitively that non-trivial solutions of the differential equationf′=f have no zeros. We give a working definition of the concept of preformal proving, as well as three examples of preformal proofs. Then we furnish several such proofs of the aforesaid fact, and we analyse these proofs in detail. Finally, we draw some conclusions for mathematics in school and in teacher training.     

Wird die Pluralität in der Erziehungswissenschaft aufgekündigt?

This paper discusses whether research following PISA might constrain the plurality of empirical and theoretical approaches in empirical educational research. The significance of plurality in the field of science is reviewed initially; followed by the paper’s central thesis. It is argued that qualitative and new quantitative empirical educational research seldom considers each other in key areas of the field, e.?g. investigations on educational inequality. Though, ‘dimming out’ perspective-wise is marked rather a distinct feature of new quantitative educational research. Using the example of research on selection-based learning environments, students’ habitus and the family’s role in educational inequality, it is shown how a reflected linkage of both perspectives and mutual reception can be substantially beneficial to the findings of both paradigms.     

Training Interventions to Foster Skill and Will of Argumentative Thinking

Argumentative thinking requires not only the skill to apply argumentative strategies such as supporting theories with evidence but also the will to apply these strategies by considering argumentative thinking to be both reasonable and worthwhile. Focusing on direct instruction for the initial acquisition of both skill and will, we developed a new short-term computer-based training intervention. We tested its effects on learning processes and learning outcomes in an experimental study with 147 German high school students. Our intervention fostered facets of both skill (i.e. a declarative knowledge about argumentation) and will (i.e., epistemic orientation, intellectual values, and epistemic knowledge). We gained additional insights into learning mechanisms, such as the mediating effects of the learners' self-explanation activities and the advantage of addressing will before skill.     

Stimulus control of behavior during the postreinforcement pause of FI schedules

Pigeons were given the opportunity to terminate certain segments of fixed intervals by pecking a control key. When 30-sec segments of negative and positive stimuli alternated across the interreinforcement interval (Experiment 1), most birds terminated a large proportion of negative segments. However, few control-key responses were made during the negative segment immediately following food presentation. Under schedules during which only one negative segment was programmed, during the first 30 sec of 1-min intervals (Experiment 2), control-key responses, when they occurred at all, were made after several seconds of the interval had elapsed. Similar findings were obtained when a peck on the control key merely changed the color on the food key (Experiment 3). These findings suggest that the post-reinforcement extinction state (Schneider, 1969) during fixed-interval schedules consists of two phases: an immediate postreinforcement inhibitory phase, followed by a second phase during which a control-key response may occur. These two phases and their associated behavior may be related to Staddon’s (1977) distinction between interim and facultative activities.     

Bernd-Christian Funk ein 65-er!

Im gro?en Bedenk- und Gedenkjahr 2008 feiert der vielf?ltig aktive Rechtswissenschafter o. Univ.-Prof. Mag. Dr. Bernd-Christian Funk seinen 65. Geburtstag; dies darf zum Anlass genommen werden, das unermüdlich wirkende Beiratsmitglied der "Zeitschrift für Hochschulrecht, Hochschulmanagement und Hochschulpolitik" zu würdigen.     

A Q-Sort measure of beliefs about abortion

Debate over the availability and use of induced abortion continues in the US. The author introduces a Q-sort procedure for assessing beliefs about abortion and presents results from its application. The measure permits the assessment of reactions to a fuller list of beliefs than has been employed in many previous studies, while being person-centered instead of more variable-centered with regard to the analyses of reactions to the abortion issue. 119 university respondents of mean age 19.6 years in a range of 18-46 years from an introductory psychology class sorted 41 items, derived in part from open-ended responses of a large community sample, into a seven-category forced distribution. 55.5% of the sample was male. Cluster analysis of respondents' sorts yielded two types reflecting pro-life orientations toward the issue and two representing pro- choice orientations. Significant differences were found among the types on eight scales of the California Psychological Inventory, including scales assessing interpersonal effectiveness, intellectual competence, and flexibility. The types did not, however, differ on scales assessing respondents' orientation toward norms. These results demonstrate the strong feasibility and utility of employing the Abortion Beliefs Q-Sort in additional studies on the issue.     

Professorenberufung gemäß UG 2002

Durch das UG 2002 wurde der Bereich der Personalrekrutierung an Universitäten in die autonome Aufgabenbesorgung der Universitätsorgane übertragen. Von diesem neuen Regelungsregime sind auch UniversitätsprofessorInnen erfasst. In diesem Zusammenhang besteht jedoch eine Fülle von Fragen – insbesondere jene, in welchem Umfang im Auswahlverfahren entsprechende Rechtsschutzperspektiven für übergangene bzw nicht berücksichtigte BewerberInnen bestehen. Dieser Fragestellung soll im folgenden Beitrag im Anschluss an die Darstellung des Berufungsverfahrens gem §§ 98 f UG 2002 nachgegangen werden.     

Effect of ski boot rear stiffness (SBRS) on maximal ACL force during injury prone landing movements in alpine ski racing: A study with a musculoskeletal simulation model

A common anterior cruciate ligament (ACL) injury situation in alpine ski racing is landing back-weighted after a jump. Simulated back-weighted landing situations showed higher ACL-injury risk for increasing ski boot rear stiffness (SBRS) without considering muscles. It is well known that muscle forces affect ACL tensile forces during landing. The purpose of this study is to investigate the effect of different SBRS on the maximal ACL tensile forces during injury prone landings considering muscle forces by a two-dimensional musculoskeletal simulation model. Injury prone situations for ACL-injuries were generated by the musculoskeletal simulation model using measured kinematics of a non-injury situation and the method of Monte Carlo simulation. Subsequently, the SBRS was varied for injury prone landings. The maximal ACL tensile forces and contributing factors to the ACL forces were compared for the different SBRS. In the injury prone landings the maximal ACL tensile forces increased with increasing SBRS. It was found that the higher maximal ACL force was caused by higher forces acting on the tibia by the boot and by higher quadriceps muscle forces both due to the higher SBRS. Practical experience suggested that the reduction of SBRS is not accepted by ski racers due to performance reasons. Thus, preventive measures may concentrate on the reduction of the quadriceps muscle force during impact.