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In this study, we examine the development of student engagement in relation to dropout. We focus on different growth trajectories of engagement between groups of students and on whether these trajectories lead to differences in the survival of the student. The development of behavioural and emotional engagement of 4063 graduates and 541 (11.7%) dropouts is examined from Year 7 to Year 12 and this development is linked to the probability of dropping out in each grade by means of a discrete-time survival mixture model. For emotional engagement, results point to a model with two different subgroups: one group starting at a high level of engagement and following a (relatively) stable pattern and the other group starting at a lower level of engagement and following a decreasing trend. For behavioural engagement, the results indicate that a three-class model showed the best fit: a high and (relatively) stable group, a high and decreasing group and a low and stable group. In terms of dropout, the unstable and low groups demonstrate a significantly higher probability of dropping out, as evidenced in the steep, declining survival curves. Different background variables are included to gain more insight into engagement and dropout, and to predict membership in the low and decreasing class. 相似文献
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Carl C. Chambers 《Journal of The Franklin Institute》1934,218(4):463-484
The results of Del Rosario on cold emission are shown to result from the fact that, through the attainment of specially good vacuum conditions and freedom from contamination, the cold electron current from the wire was suppressed up to field strengths greater than those at which measurable current was obtained in the work of previous observers. It was in fact suppressed beyond the point at which discharge started from points on the welding of the support. The results of Del Rosario are thus probably characteristic of conditions other than those pertaining to the wire, a conclusion which accounts for his current voltage curves. The formula of Fowler and Nordheim is found to apply in the measurable regions in form directly and in magnitude only if irregularities of the surface are such as to raise the field at the surface to a sufficiently high value. Breakdowns after intense heat treatment are studied and found to be caused by immeasurably small currents of electrons knocking ions from the anode. The erratic original curves obtained by previous investigators are found to be caused by successive breakdowns similar to those found after intense heating. 相似文献
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Carl Hering 《Journal of The Franklin Institute》1918,186(2):233-241
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