A kuder richardson reliability coefficient would also be. Kuderrichardson reliability coefficients kr20 in spss. Three approximations of standard error of measurement. Excel spreadsheet to calculate instrument reliability. To investigate the effect of violating the assumption of equal item difficulty on kuderrichardson kr formula 21 reliability coefficient, 670 eighthand ninth grade students were administered 26 short, homogeneous tests of mathematics concepts and skills. Both kr formula 20 and kr formula 21 were used to estimate reliability on each test. Ranges from 01 the higher the better greater than 0. Download pdf show page numbers the kuder richarson formula 20, often abbreviated as kr20, and the kuder richardson formula 21, abbreviated kr21, are measures of internal consistency for measures that feature dichotomous items. Kuder richardson formulas as noted earlier in this chapter. Kuder and richardson formula 20 real statistics using excel.
A generalization of kuderrichardson reliability formula. The fivepoints likert scale showed an average score of above four points with content validity index cvi for icvi as 0. Kuderrichardson reliability coefficients kr20 and kr21. Whenever a test or other measuring device is used as part of the data collection process, the validity and reliability of that test is important. The results are listed in the upper portion of figure 1. Just as we would not use a math test to assess verbal skills, we would not want to use a measuring device for research that was not truly measuring what we purport it to. Correlation, and kuderrichardson 20 is illustrated through a fictitious example. As a result of the study, an effective and reliable achievement test including 32 questions with intermediate difficulty level and well distinction strength created for matter changing unit is brought to the science education. The kr20, or kuderrichardson formula, measures overall test reliability. This analysis applied kr20 to determine reliability within the range of 0.
Although some qualitative researchers disagree with such applications, a link between the. Online statistics helps you in estimating the test reliability using kuderrichardson formula 21 calculator. The values of p in row 18 are the percentage of students who answered that question correctly e. Find out how the hesi rn exit exam and hesi rn specialty exams rated on the kuder richardson 20 kr20 scale for test reliability in 20172018. Based on ongoing research dating back to 1938, our assessments provide accurate results that serve as a powerful springboard for career planning. As a result of the study, an effective and reliable achievement test including 32 questions with intermediate difficulty level and well distinction strength created for matter changing unit is. Validity and reliability in assessment this work is the summarizations. Two formulas kr 20and kr 21 that were developed to estimate reliability. The familiar spearmanbrown formula is shown to be a special case of the.
The kr 20 can be used only with dichotomously scored items. Determine the reliability of the questionnaire using kuder and richardson formula 20. Reliability coefficient kuder richardson kr 20 assesses how well the test is actually measuring what you need it to. Cronbach alpha coefficient an overview sciencedirect. Paper presented at the annual meeting of the american psychological association 84th, washington, d. Cronbachs alpha is a measure used to assess the reliability, or internal consistency, of a set of scale or test items. Would the test yield the same or similar scores consistently all things being equal.
In marketing researches one of the most used reliability estimator is cronbachs alpha, introduced in 1951 by cronbach, as a generalization of the kr20 estimator created in 1937 by kuder and richardson. In psychometrics, the kuder richardson formula 20 kr20, first published in 1937, is a measure of internal consistency reliability for measures with dichotomous choices. Figure 1 kuder and richardson formula 20 for example 1. Calculating reliability of quantitative measures dr. Reliability, kuderrichardson formula the sage encyclopedia of communication research methods search form. The name of this formula stems from the fact that is the twentieth formula discussed in kuder and richardson s seminal paper on test reliability. Many authors question this estimators power and are.
One of the best known methods is the kuder richardson 20. As noted earlier in this chapter, coefficient alpha can be computed by several methods other than the general formula presented in equation 7. What is the kuderrichardson test for reliability and what. A test of the hypothesis that cronbachs alpha or kuderrichardson coefficent twenty is the same for two tests. The most useful measure is generally the kuderrichardson formula 20 kr20.
The closer the score to 1, the more reliable the test. The consistency responses examined by the rasch model interpretation on person and item reliability are explained with kuderrichardson kr20 and coefficient alpha cronbach, 1984 values. Construction of valid and reliable test for assessment of students. The approximate sampling distribution of kuderrichardson reliability coefficient twenty. It is a measure of how difficult the question was to answer. Kuderrichardson formulas 20 and 21 sage research methods. Reliability was assessed by kuderrichardson reliability coefficient and split half. If you have access to a journal via a society or association membership, please browse to your society journal, select an article to view, and follow the instructions in this box.
The theoretically best estimate of the reliability coefficient is stated in terms of a precise definition of the equivalence of two forms of a test. The reliability estimates are incorrect if you have missing data. In splithalf reliability, the results of a test, or instrument, are divided in half. With kr20, youre looking at a range of 01, where 0 is no reliability and 1 is perfect reliability. Differences between kuderrichardson formula 20 and. The data is in and the numbers tell an interesting story. I have created an excel spreadsheet to automatically calculate splithalf reliability with spearmanbrown adjustment, kr20, kr21, and cronbachs alpha. Learn vocabulary, terms, and more with flashcards, games, and other study tools. The kuderrichardson reliability coefficient and split half reliability were found 0. Using and interpreting cronbachs alpha university of. Strong correlations indicate high reliability, while weak correlations indicate the instrument may not be reliable. It is a multiple choice objective test of five options with 100 items. Kuder kuder career search with person match interest. The kuderricharson formula 20, often abbreviated as kr20, and the kuderrichardson formula 21, abbreviated kr21, are measures of.
Results obtained by the kudarrichardson formula 20 adapted for use with rkw scoring are compared with three other reliability formulas. A test of the hypothesis that cronbachs alpha or kuder. Formula 21 is a simplified and easily computable version of. The kr20 is a special case of cronbachs alpha in which the items are binary variables usually scored as 0 or 1. Various approximations to this theoretical formula are derived, with reference to several degrees of completeness of information about the test and to special assumptions. Reliability, kuderrichardson formulapage 1418 sage. Suppose you make up a multiple choice personality test that decides a yesno question, like do you belong in slytherin house. If you give the test to a bunch of people, you can use the kuderrichardson test on their results to try to tell you s.
Access to society journal content varies across our titles. Cronbach alpha is, due to its excessive use as well, a subject of controversies. Essentially it lets you know whether the exam as a whole discriminated among students who mastered the subject matter and those who did not. Rational equivalence rational equivalencekuder richardson reliability and coefficient it is based on consistency of responses to all items in the. Simple procedures for estimating interrater reliability are presented using the new spss for windows 5. The internal consistency reliability of the primary data was estimated through kuder and richardson formula 21 kr21.
The splithalf reliability test by kuderrichardson formula 20 kr 20 to obtain a homogenous reliability index value ensured internal consistency of the instrument. Measuring the validity and reliability of research instruments. In other words, the reliability of any given measurement refers to the extent to which it is a consistent measure of a concept, and cronbachs alpha is. Can spss calculate the kuder richardson 20 kr20 and kr21 coefficients of reliability for a scale. Construction of valid and reliable test for assessment of. The test statistics report provides basic statistics on the test as a whole and is useful for.
After the questions are excluded, kuder richardson 20 reliability coefficient is estimated to be 0,763. Csbqir was evaluated for its construct, inclusiveness and content validity by principal component analysis. Both the interrater reliability for averaged ratings and the intraclass correlation for a single, typical judge are derived from the repeated. The kuder career assessments are regarded as bestinclass for their validity and reliability.
After the questions are excluded, kuder richardson20 reliability coefficient is estimated to be 0,763. The kr20, or kuder richardson formula, measures overall test reliability. I want to use the kr20 to learn about the internal consistency of items. Krl20 and kr21 only work when data are entered as 0 and 1. A collection of reliability measures was introduced by kuder and richardson, 1937.
The kuderrichardson test is a more complicated version of the splithalf test. Pdf determination of reliability and validity measures. Kuderrichardson estimate of test internal consistency would the same items test the same on different forms of the test. Korb university of jos reliability overview reliability is defined as the consistency of results from a test. I use the kr20 instead of the cronbachs alpha because my items are noted on a binary scale. Kuder richardson reliability coefficients kr20 and kr21.
368 681 1289 626 1443 956 1363 1327 1322 1109 663 609 339 357 564 122 307 728 1053 1035 1120 148 1411 72 1335 46 588 516 450 103