<?xml version="1.0" encoding="utf-8"?><!DOCTYPE article  PUBLIC '-//OASIS//DTD DocBook XML V4.4//EN'  'http://www.docbook.org/xml/4.4/docbookx.dtd'><article><articleinfo><title>FAQ/kappa</title><revhistory><revision><revnumber>39</revnumber><date>2019-09-24 14:25:53</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>38</revnumber><date>2019-09-24 14:22:05</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>37</revnumber><date>2019-09-24 14:21:50</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>36</revnumber><date>2014-01-30 12:01:57</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>35</revnumber><date>2014-01-29 17:11:13</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>34</revnumber><date>2014-01-29 17:10:41</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>33</revnumber><date>2014-01-29 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href=&quot;http://abhawamnbxmf.com/&quot;&gt;abhawamnbxmf&lt;/a&gt;</revremark></revision><revision><revnumber>12</revnumber><date>2012-07-06 14:29:51</date><authorinitials>188.143.232.12</authorinitials><revremark>This is an atrclie that makes you think &quot;never thought of that!&quot;</revremark></revision><revision><revnumber>11</revnumber><date>2012-06-21 09:27:22</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>10</revnumber><date>2012-06-21 09:25:58</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>9</revnumber><date>2012-06-21 09:25:39</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>8</revnumber><date>2010-08-09 13:25:21</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>7</revnumber><date>2010-08-03 11:14:18</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>6</revnumber><date>2010-08-03 11:08:56</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>5</revnumber><date>2007-01-25 16:00:25</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>4</revnumber><date>2006-07-18 15:23:48</date><authorinitials>pc0082.mrc-cbu.cam.ac.uk</authorinitials></revision><revision><revnumber>3</revnumber><date>2006-07-18 14:13:46</date><authorinitials>pc0082.mrc-cbu.cam.ac.uk</authorinitials></revision><revision><revnumber>2</revnumber><date>2006-07-18 14:02:25</date><authorinitials>pc0082.mrc-cbu.cam.ac.uk</authorinitials></revision><revision><revnumber>1</revnumber><date>2006-07-18 13:48:11</date><authorinitials>pc0082.mrc-cbu.cam.ac.uk</authorinitials></revision></revhistory></articleinfo><section><title>Kappa statistic evaluation in SPSS</title><para>Kappa and Phi are recommended as inter-rater agreement indices with Grant MJ, Button CM and Snooker B (2017) recommending their use for binary data (see <ulink url="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5978587/">here).</ulink> </para><para>SPSS syntax available: </para><itemizedlist><listitem><para><ulink url="https://lsr-wiki-02.mrc-cbu.cam.ac.uk/statswiki/FAQ/kappa/statswiki/FAQ/kappa/kappans#">Non-square tables where one rater does not give all possible ratings</ulink> </para></listitem><listitem><para><ulink url="https://lsr-wiki-02.mrc-cbu.cam.ac.uk/statswiki/FAQ/kappa/statswiki/FAQ/kappa/multiple#">More than 2 raters</ulink> </para></listitem><listitem><para><ulink url="https://lsr-wiki-02.mrc-cbu.cam.ac.uk/statswiki/FAQ/kappa/statswiki/FAQ/ad#">An inter-rater measure based on Euclidean distances</ulink> </para></listitem></itemizedlist><para><emphasis role="strong">Note:</emphasis> Reliability as defined by correlation coefficients (such as Kappa) requires variation in the scores to achieve a determinate result. If you have a program which produces a determinate result when the scores of one of the coders is constant, the bug is in that program, not in SPSS. Each rater must give at least two ratings. </para><itemizedlist><listitem><para><ulink url="https://lsr-wiki-02.mrc-cbu.cam.ac.uk/statswiki/FAQ/kappa/statswiki/FAQ/kappa/magnitude#">Benchmarks for suggesting what makes a high kappa</ulink> </para></listitem></itemizedlist><para>There is also a weighted kappa which allows different weights to be attached to misclassifications. Warrens (2011) shows that weighted kappa is an example of a more general test of randomness. This <ulink url="https://lsr-wiki-02.mrc-cbu.cam.ac.uk/statswiki/FAQ/kappa/statswiki/FAQ/kappa?action=AttachFile&amp;do=get&amp;target=kappa.pdf">paper</ulink> by Von Eye and Von Eye (2005) gives a comprehensive insight into kappa and variants of it. These include a variant by Brennan and Prediger (1981) (computed using either this <ulink url="http://justusrandolph.net/kappa/">on-line calculator</ulink>, which also computes Cohen's kappa, or this <ulink url="https://lsr-wiki-02.mrc-cbu.cam.ac.uk/statswiki/FAQ/kappa/statswiki/FAQ/kappa?action=AttachFile&amp;do=get&amp;target=bpkappa.xls">spreadsheet</ulink>) which enables kappa to attain the maximum value of '1' comparing to a uniform distribution when the number of category ratings is not fixed. Von Eye and Von Eye's paper suggests, however, that this measure can give a misleadingly high value if the raters give different numbers of category ratings.   </para><para><ulink url="https://lsr-wiki-02.mrc-cbu.cam.ac.uk/statswiki/FAQ/kappa/statswiki/FAQ/kappa?action=AttachFile&amp;do=get&amp;target=bdkap.pdf">Bornmann and Daniel (2009)</ulink> use bootstraps (see example R code <ulink url="https://lsr-wiki-02.mrc-cbu.cam.ac.uk/statswiki/FAQ/kappa/statswiki/FAQ/BPkapCIR#">here</ulink>) to estimate the standard errors of both Cohen's and Brennan and Prediger kappas and find very close agreement between the two. On-line calculators for kappa are also <ulink url="http://www.medcalc.org/manual/kappa.php">available.</ulink> </para><para>This <ulink url="https://lsr-wiki-02.mrc-cbu.cam.ac.uk/statswiki/FAQ/kappa/statswiki/FAQ/kappa?action=AttachFile&amp;do=get&amp;target=kappayork.pdf">PDF document</ulink> gives an overview of kappa which was downloaded from a website page hosted by the University of York located <ulink url="http://www-users.york.ac.uk/~mb55/msc/clinimet/week4/kappash2.pdf">here</ulink>. Kappa can also be computed using the wkappa function in R. </para><para><emphasis role="underline">References</emphasis> </para><para>Bornmann, L and Daniel, H-D (2009). The luck of the referee draw:the effect of exchanging reviews. <emphasis>Learned Publishing</emphasis> <emphasis role="strong">22</emphasis> 117–125 </para><para>Brennan RL, &amp; Prediger DJ (1981). Coefficient kappa: Some uses, misuses, and alternatives. <emphasis>Educational and Psychological Measurement</emphasis> <emphasis role="strong">41</emphasis> 687–699. </para><para>Grant MJ, Button CM and Snooker B (2017). An Evaluation of Interrater Reliability Measures on Binary Tasks Using d-Prime. <emphasis>Applied Psychological Measurement</emphasis> <emphasis role="strong">41(4)</emphasis> 264–276.  </para><para>von Eye A &amp; von Eye M (2005). Can One Use Cohen's Kappa to Examine Disagreement? <emphasis>Methodology</emphasis> <emphasis role="strong">1(4)</emphasis> 129–142.  </para><para>Warrens MJ (2011). Chance-corrected measures for 2 × 2 tables that coincide with weighted kappa. <emphasis>British Journal of Mathematical and Statistical Psychology</emphasis> <emphasis role="strong">64(2)</emphasis> 355–365. </para></section></article>