Coefficient β As Extension of KR-21 Reliability for Summed and Scaled Scores for Polytomously-scored Tests

IF 1.1 4区教育学 Q3 EDUCATION & EDUCATIONAL RESEARCH

Applied Measurement in Education Pub Date : 2021-04-03 DOI:10.1080/08957347.2021.1890740

Rashid S. Almehrizi

{"title":"Coefficient β As Extension of KR-21 Reliability for Summed and Scaled Scores for Polytomously-scored Tests","authors":"Rashid S. Almehrizi","doi":"10.1080/08957347.2021.1890740","DOIUrl":null,"url":null,"abstract":"ABSTRACT KR-21 reliability and its extension (coefficient α) gives the reliability estimate of test scores under the assumption of tau-equivalent forms. KR-21 reliability gives the reliability estimate for summed scores for dichotomous items when items are randomly sampled from an infinite pool of similar items (randomly parallel forms). The article extends KR-21 to coefficient to estimate reliability of summed scores for test with any item scoring pattern under the same assumption of KR-21. Also, the article presents coefficient to estimate this reliability for nonlinearly scaled scores for any type of items. The article shows that coefficient is slightly different from the classical index of reliability. Results show that coefficient is not equal to the classical index of reliability for summed scores and scaled scores. Moreover, results using real data on psychological instruments reveal that different score scales yield different coefficient reliability estimates that are less than coefficient Gα by a function related to form-to-form differences in averages.","PeriodicalId":51609,"journal":{"name":"Applied Measurement in Education","volume":"34 1","pages":"139 - 149"},"PeriodicalIF":1.1000,"publicationDate":"2021-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Measurement in Education","FirstCategoryId":"95","ListUrlMain":"https://doi.org/10.1080/08957347.2021.1890740","RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"EDUCATION & EDUCATIONAL RESEARCH","Score":null,"Total":0}

引用次数: 2

Abstract

ABSTRACT KR-21 reliability and its extension (coefficient α) gives the reliability estimate of test scores under the assumption of tau-equivalent forms. KR-21 reliability gives the reliability estimate for summed scores for dichotomous items when items are randomly sampled from an infinite pool of similar items (randomly parallel forms). The article extends KR-21 to coefficient to estimate reliability of summed scores for test with any item scoring pattern under the same assumption of KR-21. Also, the article presents coefficient to estimate this reliability for nonlinearly scaled scores for any type of items. The article shows that coefficient is slightly different from the classical index of reliability. Results show that coefficient is not equal to the classical index of reliability for summed scores and scaled scores. Moreover, results using real data on psychological instruments reveal that different score scales yield different coefficient reliability estimates that are less than coefficient Gα by a function related to form-to-form differences in averages.

查看原文本刊更多论文

系数β作为多元计分测验中总和分数和标度分数的KR-21信度扩展

摘要KR-21可靠性及其扩展（系数α）给出了在tau等价形式假设下的考试成绩的可靠性估计。KR-21可靠性给出了当从无限多个相似项目（随机平行形式）中随机抽取项目时，二分项目的总分的可靠性估计。本文将KR-21扩展到系数，以估计在KR-21相同假设下，任何项目评分模式下的总分的可靠性。此外，文章还提出了系数来估计任何类型项目的非线性评分的可靠性。文章表明，该系数与经典的可靠性指标略有不同。结果表明，对于总分和量表得分，系数不等于经典的可靠性指标。此外，使用心理工具上的真实数据得出的结果表明，不同的评分量表产生了不同的系数可靠性估计值，该估计值小于系数Gα，其函数与平均值的形式差异有关。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Applied Measurement in Education Multiple-

CiteScore

2.50

自引率

13.30%

发文量

期刊介绍： Because interaction between the domains of research and application is critical to the evaluation and improvement of new educational measurement practices, Applied Measurement in Education" prime objective is to improve communication between academicians and practitioners. To help bridge the gap between theory and practice, articles in this journal describe original research studies, innovative strategies for solving educational measurement problems, and integrative reviews of current approaches to contemporary measurement issues. Peer Review Policy: All review papers in this journal have undergone editorial screening and peer review.