农药对生态系统的影响

农药是农业生产中必不可少的生产资料,但是随着农药的大量的使用,我国当前的农药污染状况不容乐观,本文综述了农药对大气、土壤、水体的污染情况及对人体健康的危害。     

金乡县部分学龄儿童营养教育效果评价

目的对学龄儿童开展营养教育的效果和途径进行评价。方法在2所小学整群抽取学生1226名,按班级随机分为单纯学生教育组、学生与家长教育组和对照组,进行3个月不同形式的营养教育;采用问卷和膳食调查的方法,分析营养教育后学生营养知识、态度、行为和膳食结构的变化。结果两教育组学生接受营养教育后,营养知识得分与对照组比较显著提高,学生和家长教育组学生饮食行为的改善更为明显。结论学校营养教育结合家长的参与是改善学生营养行为的有效途径,但需针对不同年龄段学生施以有效的教育。     

Short answer questions in an undergraduate qualifying examination: a study of examiner variability

Scripts of a short answer Final MB examination paper were re-marked by the original examiner and three colleagues. While individual question marks varied considerably, most examiners agreed quite well as to the overall rank order of candidates--although not about absolute total marks--but a few disagreed considerably. Examiners exhibited remarkably consistent idiosyncratic behaviour in terms of the distribution of marks awarded. These factors led to haphazard pass/fail and pass/distinction decisions on this particular component of the examination. Recommendations are put forward to improve the marking consistency and use of short answer question papers.     

An experimental assessment carried out in an undergraduate general practice teaching course (OSCE examination)

Professional examinations should be fair, comprehensive, objective, and appropriate to the discipline above all. If at the same time they can be made administratively easier, interesting and in themselves a teaching/learning experience, so much the better. General Practice is a difficult subject to examine in the traditional subjective manner, yet unless students and their courses are assessed then the subject loses credibility and respect in the frenetic run-up to Finals. The Objective Structured Clinical Examination seemed a more appropriate examination than any tried so far and an experiment was mounted to instruct the Liverpool University Medical School Department of General Practice Tutors in the technique and to test several station 'formats'. At this first attempt many snags were found, but some interesting lines of enquiry and further study were opened up. No attempt was made to produce an accurate mark for individual students in this test, although all were given an insight into strong and weak areas. The experiment demonstrated that an OSCE in Primary Care or General Practice is possible and can be organized. The examiners can be taught the technique reasonably quickly and need have no previous experience of formal examinations. A working Health Centre can be used.     

The feasibility of using an American National Board examination for the evaluation of Swiss candidates for licensure

A test in Internal Medicine of the American National Board of Medical Examiners was given to Swiss medical students as a graduating examination. This study dealing with the feasibility of such an enterprise describes the technical procedures and investigates the problems of translation and the validity of foreign made items. Comparison of item analyses for the 369 Swiss candidates and for a sample of 370 American candidates reveals that most items are of close comparability in difficulty, discrimination and pattern of response to the distractors. In a cross-national comparison of students' responses to the items no systematic content characteristics can be found for items favouring one group or the other. Swiss experts, in judging the validity of the items for testing Swiss students, could indeed identify in advance some of the items that proved to be less valid and more difficult for their—but also the American—students. It is concluded that a National Board examination can be as valid and suited to examine Swiss candidates for licensure as it is to examine American candidates.     

A partially self-instructional system that any teacher can develop and implement

Some authors have suggested that the teacher has two basic choices of style which can be used to influence learning: he/she can manage learning resources or he/she can function as such a resource. Part of the appeal for the authors of the course format described here is the blurring of that distinction. Functioning both as a manager and a resource appears to us a near optimal role for the teacher.