The concept of resilience with respect to indicating instruments

This paper deals particularly with those instruments of the index-and-scale and value-controlling types of the class of non-integrating instruments, as distinguished from integrating instruments and those used for comparison purposes strictly. Independent corroboration is adduced regarding the general characteristics of the hysteresis phenomena discussed in the author's earlier paper on the variance of measuring instruments.It is shown that the area of the hysteresis loop obtained on complete cyclic calibration is a measure of the energy dissipated in the operation of the instrument and that the smallness of the area of this loop, which may be used as a factor in a function exactly analogous to the resiliency in the case of other quasielastic bodies, is a measure of the excellence of the instrument as regards the reproducibility or invariance of its indications, so far as concerns mechanical sources of variation. The specific properties of the hysteresis loop are set down analytically and the physical nature and causes of the imperfect resilience of instruments are discussed in detail.Since the motion of an index or pointer through a displacement implies the existence of a motive force to bring about the deflection, in the presence of an equivalent reactive or restoring force opposing it, the essentials of a work diagram apparently always exist in the results of a properly perforined cyclic calibration. Indications are given of the methods to be followed in the process of reducing the results of the calibration to such form that the loop obtained correctly represents energy dissipation during a cycle, typifying an integral of the form

$\text{∫}\text{B}{}_{\mathrm{y}}\text{D}{}_{\mathrm{y}}\text{[Ø}{}_1\text{(Y)?Ø}{}_2\text{(Y)] dy}$

when B_y and D_y are the projections of the extremities B and D of the loop on the, axis of deflection or reading.The restrictions which surround the carrying out of cyclic calibrations in a manner calculated to obtain results of the character required are discussed, including the requirements of slow, aperiodic change of the variables, unreversed between the chosen extreme turning points, and accomplished in the absence of jarring or vibration. Attention is directed to the necessity of accustoming the instrument to the particular cycle over which it is to be calibrated, to the end of regularizing its performance.Both the form and area of the hysteresis loop should be observed, in order to arrive at regional as well as aggregate effects of the causes producing the variance. The amount and scope of the effects of vibratory treatment in modifying and diminishing the causes of lag are indicated.The possible causes of the lag known to exist in. the case of instruments using a surface of discontinuity between fluids as the indicating element are discussed, and it is shown that known phenomena perhaps hitherto unrecognized in their relation to instrument design and calibration may account for the variancy noted. Detailed experimental consideration of these factors is hoped for.Comparison of instrument performances on the basis of the hysteresis loss requires equivalence of the ranges of operation, or possibly reduction of the results on the basis of information not vet available in a form, capable of general application.The resiliency determination opens up a field for type-testing and selection of instruments on a basis quite discrete from that pertaining to the ordinary methods of calibration, in that the former permits selection between types of instruments rather than between individuals, making clearly discriminable the differences between the characteristics of given operating principles, designs of mechanical details, or qualities of workmanship. The more general methods of diminishing variance educible from the foregoing considerations are indicated.     

A New Two-Step Approach for Hands-On Teaching of Gene Technology: Effects on Students’ Activities During Experimentation in an Outreach Gene Technology Lab

Emphasis on improving higher level biology education continues. A new two-step approach to the experimental phases within an outreach gene technology lab, derived from cognitive load theory, is presented. We compared our approach using a quasi-experimental design with the conventional one-step mode. The difference consisted of additional focused discussions combined with students writing down their ideas (step one) prior to starting any experimental procedure (step two). We monitored students’ activities during the experimental phases by continuously videotaping 20 work groups within each approach (N = 131). Subsequent classification of students’ activities yielded 10 categories (with well-fitting intra- and inter-observer scores with respect to reliability). Based on the students’ individual time budgets, we evaluated students’ roles during experimentation from their prevalent activities (by independently using two cluster analysis methods). Independently of the approach, two common clusters emerged, which we labeled as ‘all-rounders’ and as ‘passive students’, and two clusters specific to each approach: ‘observers’ as well as ‘high-experimenters’ were identified only within the one-step approach whereas under the two-step conditions ‘managers’ and ‘scribes’ were identified. Potential changes in group-leadership style during experimentation are discussed, and conclusions for optimizing science teaching are drawn.     

E-learning with multiple-try-feedback: Can hints foster students’ achievement during the semester?

Educational technology research and development - E-learning opportunities have become an increasingly important component of university education. Various laboratory studies have shown that...     

Toward Synergizing Educational Research and Movement Sciences: a Dialogue on Learning as Developing Perception for Action

Educational Psychology Review - What could possibly be a meaningful conversation between educational researchers and movement scientists? Curiously, they have much in common. Both groups of...     

A process for the critical analysis of instructional theory

Some have argued for a common language in the field of instructional design in an effort to reduce misunderstandings and simplify a multitude of synonymous terms and concepts. Others feel that this goal is undesirable in that it precludes development and flexibility. In this article we propose an ontology-building process as a way for readers to compare and analyze terms and concepts across theories. This process entails the development of categories that emerge from the literature, and the comparison of theories across categories. Such a process can reveal broader concepts that exist beyond specific theoretical terminology, differences in meanings behind common terms used by theorists, a greater understanding of the theorists’ intent, and discontinuities and gaps within the theoretical literature.     

Effektivität schulischer Sprachförderung bei Erstklässlern mit Sprachentwicklungsstörungen

The present study examines the language development of N = 48 children with specific language impairments. All pupils were primary students in their first year. They all were tested with the standardized test (SET 5-10). N = 24 children received special tuition. All other children participated in the common tutoring structures of teaching in Mecklenburg-Western Pomerania. The results of this study show a moderate but significant progress in language development for both groups.