How do you calculate reliability using Kuder-Richardson?
σ2 = variance of the total scores of all the people taking the test = VARP(R1) where R1 = array containing the total scores of all the people taking the test. Values range from 0 to 1. A high value indicates reliability, while too high a value (in excess of .
What is a KR-20 score?
KR-20 scores range from 0-1 (although it is possible to obtain a negative score); 0 indicates no reliability and 1 represents perfect test reliability. A KR-20 score above 0.70 is generally considered to represent a reasonable level of internal consistency reliability.
What is the difference between KR-20 and coefficient alpha?
All Answers (8) Both KR20 and Cronbach’s alpha are measures of internal consistency (broadly referred to as coefficient alpha). Under ideal circumstances (e.g., no missing data, unidimensionality of items) and with binary items, KR20 and Cronbach’s alpha should essentially be the same.
What is the difference between KR-20 and KR 21?
KR-21 is a simplified version of KR-20, which can be used when the difficulty of all items on the test are known to be equal. Like KR-20, KR-21 was first set forth as the twenty-first formula discussed in Kuder and Richardson’s 1937 paper. Similarly to KR-20, K is equal to the number of items.
What is a good KR-20 for an exam?
These high-stakes exams are expected to maintain consistent KR-20 scores higher than 0.80. With smaller sample sizes, course exams with a KR20 score higher than 0.60 to 0.65 should be considered consistent and reliable, while it is recommended to maintain scores higher than 0.70.
What is Kuder Richardson coefficient?
KR-20/KR-20 are measures of test reliability, Kuder-Richardson Formula 20, or KR-20, is a measure reliability for a test with binary variables (i.e. answers that are right or wrong). The KR20 is used for items that have varying difficulty. For example, some items might be very easy, others more challenging.
What is the difference between Kuder Richardson 20 and 21?
What does a low KR-20 mean?
Usually, a KR20 figure of 0.8 is considered the minimal acceptable value. A figure below 0.8 could indicate that the exam was not reliable. The KR20 is influenced by difficulty, spread in scores, and length of the examination.
What is a good KR20?