The effects of audio cueing and an instructions, feedback and praise package on the distribution of teacher praise to students of differing on-task levels

In an audio cueing system, a teacher is presented with randomly spaced auditory signals via tape recorder or intercom. The teacher is instructed to praise a child who is on-task each time the cue is presented. In this study, a baseline was obtained on the teacher's praise rate and the children's on-task behaviour in a Grade 5 class of 37 students. Children were then divided into high, medium and low on-task groups. Followinq baseline, the teacher's praise rate and the children's on-task behaviour were observed under the following successively implemented conditions: (l) Audio Cueing 1: Audio cueing at a rate of 30 cues per hour was introduced into the classroom and remained in effect during subsequent conditions. A group of consistently low on-task children were delineated. (2) Audio Cueing Plus 'focus praise package': Instructions to direct two-thirds o£ the praise to children identified by the experimenter (consistently low on-task children), feedback and experimenter praise for meeting or surpassing the criterion distribution of praise ('focus praise package') were introduced. (3) Audio Cueing 2: The 'focus praise package' was removed. (4) Audio Cueing Plus 'increase praise package': Instructions to increase the rate of praise, feedback and experimenter praise for improved praise rates ('increase praise package') were introduced. The primary aims of the study were to determine the distribution of praise among hi~h, medium and low on-task children when audio cueinq was first introduced and to investigate the effect of the 'focus praise package' on the distribution of teacher praise. The teacher distributed her praise evenly among the hiqh, medium and low on-task groups during audio cueing 1. The effect of the 'focus praise package' was to increase the percentage of praise received by the consistently low on-task children. Other findings tended to suggest that audio cueing increased the teacher's praise rate. However, the teacher's praise rate unexpectedly decreased to a level considerably below the cued rate during audio cueing 2. The 'increase praise package' appeared to increase the teacher's praise rate above the audio cueing 2 level. The effect of an increased praise rate and two distributions of praise on on-task behaviour were considered. Significant increases in on-task behaviour were found in audio cueing 1 for the low on-task group, in the audio cueing plus 'focus praise package' condition for the entire class and the consistently low on-task group and in audio cueing 2 for the medium on-task group. Except for the high on-task children who did not change, the effects of the experimental manipulations on on-task behaviour were e quivocal. However, there were some indications that directing 67% of the praise to the consistently low on-task children was more effective for increasing this group's on-task behaviour than distributing praise equally among on-task groups.

Modeling the distribution of crossovers and interference with mice DNA data

Chiasma and crossover are two related biological processes of great importance in the understanding genetic variation. The study of these processes is straightforward in organisms where all products of meiosis are recovered and can be observed. This is not the case in mammals. Our understanding of these processes depends on our ability to model them. In this study I describe the biological processes that underline chiasma and crossover as well as the two main inference problems associated with these processes: i) in mammals we only recover one of the four products of meiosis and, ii) in general, we do not observe where the crossovers actually happen, but we find an interval containing type-2 censored information. NPML estimate was proposed and used in this work and used to compare chromosome length and chromosome expansion through the crosses.