## Kappa Test Of Agreement

Kappa accepts its maximum theoretical value of 1 only if the two observers distribute equal codes, i.e. if the corresponding amounts of rows and columns are identical. Everything is less than a perfect match. Nevertheless, the maximum value that kappa could reach in the case of unequal distributions makes it possible to interpret the actually conserved value of kappa. The equation for the maximum κ is: The innovative work that Kappa introduced as a new technique was published in 1960 by Jacob Cohen in the journal Educational and Psychological Measurement.  To calculate pe (probability of random concordance), we find that: Z 1 – α / 2 = 1.965 {displaystyle Z_ {1-alpha /2}= 1.965} is the normal standard percentrtil, if α = 5% {displaystyle alpha =5%} and S E κ = p o ( 1 − p o ) N ( 1 − p e) 2 {displaystyle SE_{kap = {{p_{o} (1-p_{o}} {over {N(1-p_{e}{2}} We can see that the «Simple Kappa» provides the estimated value of Kappa of 0.389 with its asymptotic default error (ASE) of 0.0598. The difference between compliance with the agreement and the expected independent concordance is about 40% of the maximum possible difference. Based on the recorded 95% confidence interval, \$kappa\$ falls somewhere between 0.27 and 0.51, indicating only a moderate match between Siskel and Ebert. The weighted Kappa coefficient is 0.57 and the asymptotic confidence interval is 95% (0.44, 0.70). This indicates that the match between the two radiologists is modest (and not as strong as the researchers had hoped).

Before I get to Cohen`s kappa, I would first like to lay an important foundation for validity and reliability. When we talk about validity, we care about how well a test measures what it claims to measure or, in other words, what exactly is the method of the test. On the other hand, reliability is rather to know to what extent a test under constant conditions gives similar results or, in other words, the accuracy of a test. Therefore, the standard kappa error for the data in Figure 3, P = 0.94, pe = 0.57 and N = 222 Quanta Healthcare Solutions, Inc. (2002). Calculation of the kappa coefficient for 2 observations by 2 observers. The medical algorithms project. Retrieved on the 2nd As noted by Marusteri and Bacarea (9), on January pi_1er, 2003 by www.medal.org (kappa=dfrac{sumpi_ pi_{ii}-sumpi_{pi_ i+}} there is never 100% certainty about the research results, even if statistical significance is reached. . . .