Determine the reliability of the questionnaire using kuder and richardson formula 20. Psychometric validity and reliability statistics in r. Pdf determination of reliability and validity measures of a. An approximation to the sampling distribution of kuderrichardson reliability formula 20 is derived, using its algebraic equivalent obtained through an itemsbysubjects analysis of variance.
Item analysis with spss software linkedin slideshare. The kuderrichardson formula 21 as a splithalf coefficient. Correlation between forms, guttman splithalf reliability, spearmanbrown reliability equal and unequal length, and coefficient alpha for each half. 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. To that end, it is necessary to test the validity and reliability to determine whether the instrument used in the study are valid and reliable. How to use spss kuder richardson 20 kr20 reliability analysis. Although some recommend using the kr20 kuder richardson coefficient if the data are dichotomous, cronbachs coefficient alpha and kr20 yield the same value. Differences between kuderrichardson formula 20 and. How to use spss kuderrichardson20 kr20 reliability. Rumus kr 20 dan tutorial cara hitung dengan excel uji statistik. 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 one way of measuring the strength of that consistency.
So, you can get what you need from the reliability procedure. Alpha should be calculated whenever possible, but kr21 can provide reasonable reliability estimates for tests with dichotomous items. The kr20, or kuder richardson formula, measures overall test reliability. For kr21 all you need is the mean score on the test, the standard deviation, and the number of items k. The kr20 is a special case of cronbachs alpha in which the items are binary variables usually scored as 0 or 1. I want to use the kr20 to learn about the internal consistency of items. How to use spss kuder richardson 20 kr20 reliability analysis duration. It assess the intern consistency reliability of a test of subtest made up of binary items, two psychometric methods, kuder richardson formula 20 9kr 20. Case iv of the kuderrichardson series, their formula 21, is derived as a generalized splithalf spearmanbrown coefficient. Kuderrichardson formula 21 calculator for test reliability. Kuderrichardson reliability coefficients kr20 in spss.
Kuderrichardson formula 20 21 correlation is determined from a single administration of a test through a study of score variances. The approximate sampling distribution of kuderrichardson. Kudarrichardson 20 cannot be used for response sets that have three or more. Kr20 is a special computational case of cronbachs alpha. Rumus kr 20 dan tutorial cara hitung dengan excel uji. Oct 25, 2015 this video demonstrates how to perform a kuder richardson 20 kr20 test of internal consistency in spss. To investigate the effect of violating the assumption of equal item difficulty on kuderrichardson kr formula 21. Kuderrichardson formula 20, or kr20, is a measure reliability for a test with binary variables i.
Kuderrichardson reliability coefficients kr20 and kr21 ibm. Feb 27, 2012 simple procedures for estimating interrater reliability are presented using the new spss for windows 5. A high value for alpha does not imply that the measure is unidimensional. Case iv of the kuder richardson series, their formula 21, is derived as a generalized splithalf spearmanbrown coefficient. This video demonstrates how to perform a kuderrichardson 20 kr20 test of internal consistency in spss. A break variable does not need to be designated in current versions of spss statistics when the aggregation is performed over the full data set. Berikut dibawah ini adalah rumus kuder richardson 20. It assess the intern consistency reliability of a test of subtest made up of binary items, two psychometric methods, kuder richardson formula 20 9k. Kuder and richardson 1937 special cases of cronbachs more general equation for parallel tests. Although some recommend using the kr20 kuderrichardson coefficient if the data are dichotomous, cronbachs coefficient alpha and kr20 yield the same value. Can spss calculate the kuderrichardson 20 kr20 and kr21 coefficients of reliability for a scale. To investigate the effect of violating the assumption of equal item difficulty on kuder richardson kr formula 21 reliability coefficient, 670 eighthand ninth grade students were administered 26 short, homogeneous tests of mathematics concepts and skills. Results obtained by the kudar richardson formula 20 adapted for use with rkw scoring are compared with three other reliability formulas. Thermuohp biostatistics resource channel 70,708 views.
Note that the matrix or ame should be at the item level and that it needs to be numeric not characters or factors. 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. The kudar richardson 20 kr20 formula generates a raw reliability coefficient for survey items that use these response sets. Get access to 16,000 woodworking plans, download 50 free plans. In psychometrics, the kuderrichardson formula 20 kr20, first published in 1937, is a measure of internal consistency reliability for measures with dichotomous choices. Consistency can be measured with splithalf testing and the kuder richardson test. The length of the test a test with more items will have a higher reliability, all other things being equal. Both kr20 and cronbachs alpha are measures of internal consistency broadly referred to as coefficient alpha. Apr 28, 2018 how to test reliability method alpha using spss instruments are valid and reliable research is a necessary condition to obtain highquality research results. How to use spss kuderrichardson20 kr20 reliability analysis. I am trying to figure out how to adapt the kruderrichardson formula. How to test reliability method alpha using spss spss tests. Conducting a kuderrichardson 20 test kr20 in spss youtube. Richardson, one was preferred, which was known to be kuder richardson formula 20.
Eric ed074095 an assessment of the kuderrichardson. The theoretical distribution is compared to empirical estimates of the sampling distribution to assess how crucial certain assumptions are. Measuring the validity and reliability of research. The basic assumption employed is shown to be sufficient to justify the. The kuderricharson formula 20, often abbreviated as kr20, and the kuderrichardson. The basic assumption employed is shown to be sufficient to justify the various assumptions used in derivations by other authors. In addition, kr20 computes the item difficulty proportion of right answers, the average value of item difficulty, the item variance, the itemtest pointbiserial correlation coefficients, and the average value of itemtest correlation coefficients. Cronbachs alpha is a statistic for investigating the internal consistency of a questionnaire cronbach, 1951. Kuder and richardson formula 20 real statistics using excel. The values of p in row 18 are the percentage of students who answered that question correctly e. How to test reliability method alpha using spss instruments are valid and reliable research is a necessary condition to obtain highquality research results. Psychology definition of kuder richardson formulas. Hi everybody, i need to calculate internal consistency reliability, using kuderrichardson formula 20 i was wondering if someone can explain how to calculate it using spss 20.
The name of this formula stems from the fact that is the twentieth formula discussed in kuder and richardsons seminal paper on. I have created an excel spreadsheet to automatically calculate splithalf reliability with spearmanbrown adjustment, kr20, kr21, and cronbachs alpha. Education software downloads spss by ibm and many more programs are available for instant and free download. Describes how to calculate the kuder and richardson formula 20 kr20 and. Stata module to calculate kuderrichardson coefficient. Rumus kuder richardson 20 apabila pada artikel sebelumnya kita sudah membahas cara perhitungan reliabilitas instrumen dengan excel yang meliputi uji cronbach alpha, split half dan spearman brown, maka dalam artikel ini kita akan membahas cara perhitungan rumus kr 20 dengan menggunakan excel. The content of the test generally, the more diverse the subject matter tested and the testing techniques used, the lower the reliability. The consistency responses examined by the rasch model interpretation on person and item reliability were explained with kuderrichardson kr20 and coefficient alpha cronbach, 1984 values. Dear all, i am checking how to do a kuderrichardson reliability coefficients kr20 in spss. Krl20 and kr21 only work when data are entered as 0 and 1. An approximation to the sampling distribution of kuder richardson reliability formula 20 is derived, using its algebraic equivalent obtained through an itemsbysubjects analysis of variance. Download pdf show page numbers the kuderricharson formula 20, often abbreviated as kr20, and the kuderrichardson formula 21, abbreviated kr21, are measures of internal consistency for measures that feature dichotomous items. Kuderrichardson reliability coefficients kr20 and kr21. Simple procedures for estimating interrater reliability are presented using the new spss for windows 5.
I use the kr20 instead of the cronbachs alpha because my items are noted on a binary scale. Both the interrater reliability for averaged ratings and the intraclass correlation for a single, typical judge are derived from the repeatedmeasures anova output in the reliability program. The kr20 is used to evaluate internal consistency among dichotomous variables. Reliability coefficients lambda 1 through lambda 6. Excel spreadsheet to calculate instrument reliability. If, in addition to measuring internal consistency, you wish to provide evidence that the scale. Cronbachs alpha is a measure used to assess the reliability, or internal consistency, of a set of scale or test items. In addition, kr20 computes the item difficulty proportion of right. Essentially it lets you know whether the exam as a whole discriminated among students who mastered the subject matter and.
Statistics that are reported by default include the number of cases, the number of items, and reliability estimates as follows. Dec 19, 2012 how to use spss kuder richardson 20 kr20 reliability analysis. Reliability refers to how consistent the results from the test are, or. The reliability estimates are incorrect if you have. Download pdf show page numbers the kuderricharson formula 20, often abbreviated as kr20, and the kuderrichardson formula 21, abbreviated kr21, are measures of internal consistency for. 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. Pdf determination of reliability and validity measures. The kuder richardson formula kr20 and the kuder richardson formula 21 kr21. Kuderrichardson 20 kr20 scale reliability calculation can spss calculate the kr20 reliability figure for assessing scales that are composed of dichotomous items. A metaanalytic method that combines estimates of reliability across studies in order to calculate an estimate based on multiple indicators of reliability.
It is considered to be a measure of scale reliability. Consistency is a measure of reliability through similarity within the test, with individual questions giving predictable answers every time. The reliability estimates are incorrect if you have missing data. What is the difference between kuderrichardson kr20 and. Kr20 kuderrichardson formula 20 is an index of the internal consistency reliability of a measurement instrument, such as a test, questionnaire, or inventory. Results obtained by the kudarrichardson formula 20 adapted for use with rkw scoring are compared with three other reliability formulas. Both the interrater reliability for averaged ratings and the intraclass.
The current research applied kr20 to determine reliability within the range of 0. Reliability test were also conducted in addition to the item analysis to observe the quality of the test as a whole. Based on parallel tests administered at the same sitting the kr 20 estimates are compared with alternateform correlations and with oddeven correlations adjusted by the spearmanbrown prophecy formula. Can spss calculate the kuder richardson 20 kr20 and kr21 coefficients of reliability for a scale. Alpha is a general version of the kuderrichardson coefficient of. Cronbachs alpha is a measure of internal consistency, that is, how closely related a set of items are as a group. Using and interpreting cronbachs alpha university of. Differences between kuderrichardson formula 20 and formula.
Rumus kuder richardson 20 apabila pada artikel sebelumnya kita sudah membahas cara perhitungan reliabilitas instrumen dengan excel yang meliputi. Computes the reliability coefficient of a set of dichotomous items, whereas cronbachs alpha is used for multipoint scales. Online statistics helps you in estimating the test reliability using kuderrichardson formula 21 calculator. Kuderrichardson 20 kr20 scale reliability calculation.
The reliability procedure can calculate alpha and therefore can calculate kr20 for binary item variables. May 25, 2012 dear all, i am checking how to do a kuderrichardson reliability coefficients kr20 in spss. You can select various statistics that describe your scale and items. How to enter data each question of the questionnaire results in one. Kudar richardson 20 is run the exact same way as cronbachs alpha in spss and interpreted the same way as well. This calculates kuder richarson 20 for a given matrix or ame. Reliability, kuderrichardson formulapage 1418 sage. Based on parallel tests administered at the same sitting the kr. For instance, the spss program can calculate kr20 as a special case of cronbachs alpha. The use of the theoretical distribution for testing hypotheses. Figure 1 kuder and richardson formula 20 for example 1 the values of p in row 18 are the percentage of students who answered that question correctly e. Although it can be applied to any test item responses that are dichotomously scored, it is most often used in classical psychometric analysis of psychoeducational tests and, as such. The kudarrichardson 20 kr20 formula generates a raw reliability coefficient for survey items that use these response sets.
Kudar richardson 20 cannot be used for response sets that have three or more levels. Cronbachs alpha continuous and dichotomous data in spss. Kuder richardson formula 20 21 correlation is determined from a. Figure 1 kuder and richardson formula 20 for example 1. Essentially it lets you know whether the exam as a whole discriminated among students who mastered the subject matter and those who did not. The results are listed in the upper portion of figure 1.
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