```Date: Tue, 14 Jun 2005 21:09:40 -0700 Reply-To: thecrickethunter@YAHOO.COM Sender: "SAS(r) Discussion" From: thecrickethunter@YAHOO.COM Organization: http://groups.google.com Subject: ANCOVA with repeated measures Comments: To: sas-l@uga.edu Content-Type: text/plain; charset="iso-8859-1" Dear all, I posted the following question at the SPSS discussion group, and I've got no response. Hopefully, some of you are bilingual and respond to my question. I recorded cricket calling songs of four populations that were divided into two zones, allopatric and sympatric zones. Sympatry means the cricket species occurs with other cricket species of interest, and allopatry means the cricket species occurs alone. In addition to these two variables ('zone' and 'population'), I also noted 'temperature' and 'age' for each calling song recording, which may be covariates. A list of variables: Zone: (allopatric or sympatric) Pop: population, nested within zone, four populations, 2 for each zone Indi: individuals, 8-14 individuals per population Tmp: temperature, varying covariate Age: age, varying covariate Calling song characters: response variables Both covariates, tmp and age, are varying covariates. Each cricket in a population was recorded once in one of three temperature ranges (18-20, 22-24, 26-28 degree C). I tried to record calling songs for all three temperature ranges for each cricket, but not all crickets were recorded for all three temperature ranges. I included crickets that were recorded at least twice for the analyses. My ultimate goal from this analysis is whether there is a significant zone effect. That is, whether calling song characters were different between allopatric and sympatric zones throughout the temperature range. The following is the syntax of my analysis. MIXED cro BY zone pop indi WITH age tmp /FIXED = zone pop(zone) indi(pop(zone)) | SSTYPE(3) /METHOD = REML /PRINT = COVB LMATRIX TESTCOV SOLUTION G /RANDOM = age tmp age*zone tmp*zone | COVTYPE(ID) /REPEATED = age tmp | SUBJECT(indi) /TEST = 'Contrasts of zone' zone 1 -1 /TEST = 'Contrasts of population' pop(zone) 1 0 -1 -1 /TEST = 'Contrasts of population' pop(zone) 0 1 -1 -1 /TEST = 'Contrasts of population' pop(zone) 1 -1 0 0. In the results, the zone effect seems to be nothing as you can see below. Type III Tests of Fixed Effects Source Num df Denom df F Sig. Intercept 1 61.0 18.3 .000 Zone 1 9.3 .40 .541 Pop(Zone) 2 39.2 28.9 .000 Indi(Pop(zone)) 42 203.3 2.9 .000 However, in an separate test when I asked the contrast question, the allopatric and sympatrix zones are different. /TEST = 'Contrasts of zone' zone 1 -1 whether the sympatric and allopatric zones are different? Contrasts Estimates SE DF TestValue t Sig. L1 1.44 .70 15.8 0 2.1 .055 Why are these two results different? In a graphic analysis, there seems to be interaction between zone and temperature. Is this interaction anything to do with these results? Any advice would be appreciated. Cricket Hunter ```

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