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SPSS® 12.0 Command Syntax Reference

SPSS® 12.0 Command Syntax Reference

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MANOVA: Repeated Measures 889<br />

• All of the dependent variables corresponding to each measure should be listed together<br />

and ordered so that the within-subjects factor named last on the WSFACTORS subcommand<br />

varies most rapidly.<br />

Example<br />

MANOVA TEMP1 TO TEMP6, WEIGHT1 TO WEIGHT6 BY GROUP(1,2)<br />

/WSFACTORS=DAY(3) AMPM(2)<br />

/MEASURE=TEMP WEIGHT<br />

/WSDESIGN=DAY, AMPM, DAY BY AMPM<br />

/PRINT=SIGNIF(HYPOTH AVERF)<br />

/DESIGN.<br />

• There are 12 dependent variables: 6 temperatures and 6 weights, corresponding to morning<br />

and afternoon measurements on three days.<br />

• WSFACTORS identifies the two factors (DAY and AMPM) that distinguish the temperature<br />

and weight measurements for each subject. These factors define six within-subjects cells.<br />

• MEASURE indicates that the first group of six dependent variables correspond to TEMP<br />

and the second group of six dependent variables correspond to WEIGHT.<br />

• These labels, TEMP and WEIGHT, are used on the output requested by PRINT.<br />

• WSDESIGN requests a full factorial within-subjects model. Because this is the default,<br />

WSDESIGN could have been omitted.<br />

RENAME Subcommand<br />

Because any repeated measures analysis involves a transformation of the dependent variables,<br />

it is always a good idea to rename the dependent variables. Choose appropriate names<br />

depending on the type of contrast specified for within-subjects factors. This is easier to do if<br />

you are using one of the orthogonal contrasts. The most reliable way to assign new names is<br />

to inspect the transformation matrix.<br />

Example<br />

MANOVA LOW1 LOW2 LOW3 HI1 HI2 HI3<br />

/WSFACTORS=LEVEL(2) TRIAL(3)<br />

/CONTRAST(TRIAL)=DIFFERENCE<br />

/RENAME=CONST LEVELDIF TRIAL21 TRIAL312 INTER1 INTER2<br />

/PRINT=TRANSFORM<br />

/DESIGN.<br />

• This analysis has two within-subjects factors and no between-subjects factors.<br />

• Difference contrasts are requested for TRIAL, which has three levels.<br />

• Because all orthonormal contrasts produce the same F test for a factor with two levels,<br />

there is no point in specifying a contrast type for LEVEL.<br />

• New names are assigned to the transformed variables based on the transformation matrix.<br />

These names correspond to the meaning of the transformed variables: the mean or<br />

constant, the average difference between levels, the average effect of trial 2 compared to<br />

1, the average effect of trial 3 compared to 1 and 2; and the two interactions between<br />

LEVEL and TRIAL.

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