非线性等值转换在大规模教育考试中的应用研究

Research of Application of Nonlinear Equivalent Conversion for Large-Scale Educational Test

：通过例证分析了线性转换（标准分转换）存在的问题，研究等值转换应该实现的基本目标；通过例证分 析研究应用ＬＩ函数完成的Ｌ变换，并将导出的“水平分”ＬＳ与Ｔ 标准分进行比较。结果表明：Ｌ变换在保持变换 前后分数分布形态不变、均值趋于统一的前提下，还能实现各版本原始最高分统一变换为设定满分，原始零分仍为 零分。Ｌ变换克服了“Ｔ 标准分”难以直观反映考生水平的问题，特别是解决了“Ｔ 标准分”带来的不同版本考试中 拔尖考生的成绩横向可比性问题。从而实现了针对不同考试版本、不同科目组合，都可以统一划定录取分数线。 为“科目任意组合，录取统一划线”找出了科学的方法，提供了可靠的依据。

The application a novel nonlinear equivalent conversion function， L-- Function， is reported and analyzed in the paper. Firstly， the problems of liner conversion (standardized T-conversion) are analyzed by through examples； the ams of test equating are discussed. And then， the achievement of application of L--Function is given by examples. The result indicates that L--function， which ensure that score distribution keep unchanged after conversion and average score of each test version approach preset value， can realize that raw top scores of different test versions are converted to uniformly preset full score， raw zero is still zero. L--function can solve the problem that the actual level of candidate cannot be reported in- tuitively by T-score， meanwhile， LS s comparable between the achievements of top-notch examinees who take part in d i fferent test versions， which can not be done by T-score. It w il realize that we can preset same admission requirement to d i fferent test versions， therefore， t proposes a scientific methods and relia- ble basis for score conversion of mixed test.