<?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/pagesL</title><revhistory><revision><revnumber>16</revnumber><date>2017-08-25 10:58:03</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>15</revnumber><date>2013-03-08 10:17:09</date><authorinitials>localhost</authorinitials><revremark>converted to 1.6 markup</revremark></revision><revision><revnumber>14</revnumber><date>2011-03-18 12:36:13</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>13</revnumber><date>2011-03-18 12:36:00</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>12</revnumber><date>2011-03-18 12:35:47</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>11</revnumber><date>2011-03-18 12:35:11</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>10</revnumber><date>2011-03-16 17:05:27</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>9</revnumber><date>2011-03-16 17:03:10</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>8</revnumber><date>2011-03-16 17:02:29</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>7</revnumber><date>2011-03-16 17:00:06</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>6</revnumber><date>2011-03-16 16:53:37</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>5</revnumber><date>2011-03-16 16:50:54</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>4</revnumber><date>2011-03-16 16:48:46</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>3</revnumber><date>2011-03-16 16:47:45</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>2</revnumber><date>2011-03-16 16:47:27</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>1</revnumber><date>2011-03-16 16:35:11</date><authorinitials>PeterWatson</authorinitials></revision></revhistory></articleinfo><section><title>Page's nonparametric trend test for levels of a repeated measures factor</title><para>Siegal and Castellan (1981, pp.184-188) describe a nonparametric test, Page's L test, which is similar to a one-way repeated measures ANOVA contrast of a trend. The presence of a trend in the response suggests increasing scores with conditions, ordered apriori. The trend being tested, unlike the ANOVA contrast approach, is not of a particular form, and is, for example, not necessarily linear. The single response is measured repeatedly under different conditions on the same subject. </para><para>Page's L test can be performed using this <ulink url="https://imaging.mrc-cbu.cam.ac.uk/statswiki/FAQ/pagesL/statswiki/FAQ/pagesL?action=AttachFile&amp;do=get&amp;target=pagesL.xls">spreadsheet</ulink> inputting the scores for each test made by each subject. The output from the spreadsheet consists of a test statistic, L, which represents the degree of association between the ordered conditions and the response (the higher the value of L the stronger the association) and a chi-square statistic which Siegal and Castellan say can be used for statistical significance when there are more than 20 subjects for three conditions or more than 12 subjects for between 4 and 10 conditions or any number of subjects when there are more than 10 conditions. If this is not the case critical values of L contained in Table N of their book (also given <ulink url="https://imaging.mrc-cbu.cam.ac.uk/statswiki/FAQ/pagesL/statswiki/FAQ/pagetables#">here</ulink>) should be used (pp. 354-355) which in turn are taken from the original paper of Page (1963). The L statistic is simply the product of the group rank (ordered between 1 and the number of groups) and the rank of each score where each subject score is ranked within subject, from 1 to the number of conditions, with average ranks given for tied scores. </para><para>Unlike Jonckheere's nonparametric trend test for between subjects groups and the ANOVA parametric contrast tests of trend (both between and within subjects) both described elsewhere on the statswiki, Page's L test is not available in SPSS (at least upto version 16!). There is a page.trend.test procedure in R but please note that this R procedure, unlike the above spreadsheet and Siegal and Castellan, does not rank the observations in any way but uses raw values. </para><para><emphasis role="underline">References</emphasis> </para><para>Page EB (1963). Ordered hypotheses for multiple treatments: a significance test for linear ranks. <emphasis>Journal of the American Statistical Association</emphasis> <emphasis role="strong">58</emphasis> 216-230. For CBSUers:This book is available for borrowing from the CBSU library. </para><para>Siegel S and Castellan Jr. NJ (1981). Nonparametric statistics for the behavioral sciences. <ulink url="https://imaging.mrc-cbu.cam.ac.uk/statswiki/FAQ/pagesL/statswiki/McGraw#">McGraw</ulink>-Hill:New York. </para></section></article>