Chan Wing-shing
a Office of Educational Services, Faculty of Medicine , The Chinese University of Hong Kong , Shatin , Hong Kong.
Teach Learn Med. 2014;26(4):364-5. doi: 10.1080/10401334.2014.945031.
The commonly used norm-referenced grading assigns grades to rank-ordered students in fixed percentiles. It has the disadvantage of ignoring the actual distance of scores among students.
A simple norm-referenced grading via standard deviation is suggested for routine educational grading.
The number of standard deviation of a student's score from the class mean was used as the common yardstick to measure achievement level. Cumulative probability of a normal distribution was referenced to help decide the amount of students included within a grade. RESULTS of the foremost 12 students from a medical examination were used for illustrating this grading method.
Grading by standard deviation seemed to produce better cutoffs in allocating an appropriate grade to students more according to their differential achievements and had less chance in creating arbitrary cutoffs in between two similarly scored students than grading by fixed percentile.
Grading by standard deviation has more advantages and is more flexible than grading by fixed percentile for norm-referenced grading.
常用的常模参照评分法按照固定百分位数对排名的学生进行评分。其缺点是忽略了学生之间分数的实际差距。
建议采用一种通过标准差进行的简单常模参照评分法用于常规教育评分。
用学生成绩与班级平均分的标准差数量作为衡量成绩水平的通用标准。参考正态分布的累积概率来帮助确定一个等级内包含的学生数量。以一次医学考试中前12名学生的成绩为例来说明这种评分方法。
与固定百分位数评分相比，标准差评分似乎能更好地根据学生的差异成绩为他们分配合适的等级，并且在两个成绩相近的学生之间产生任意划分界限的可能性更小。
对于常模参照评分，标准差评分比固定百分位数评分更具优势且更灵活。
