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SPSS® 12.0 Command Syntax Reference

SPSS® 12.0 Command Syntax Reference

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884 MANOVA: Repeated Measures<br />

Example<br />

MANOVA Y1 TO Y4 BY GROUP(1,2)<br />

/WSFACTORS=YEAR(4)<br />

/CONTRAST(YEAR)=POLYNOMIAL<br />

/RENAME=CONST, LINEAR, QUAD, CUBIC<br />

/PRINT=TRANSFORM PARAM(ESTIM)<br />

/WSDESIGN=YEAR<br />

/DESIGN=GROUP.<br />

• WSFACTORS immediately follows the MANOVA variable list and specifies a repeated<br />

measures analysis in which the four dependent variables represent a single variable<br />

measured at four levels of the within-subjects factor. The within-subjects factor is called<br />

YEAR for the duration of the MANOVA procedure.<br />

• CONTRAST requests polynomial contrasts for the levels of YEAR. Because the four variables,<br />

Y1, Y2, Y3, and Y4, in the working data file represent the four levels of YEAR, the<br />

effect is to perform an orthonormal polynomial transformation of these variables.<br />

• RENAME assigns names to the dependent variables to reflect the transformation.<br />

• PRINT requests that the transformation matrix and the parameter estimates be displayed.<br />

• WSDESIGN specifies a within-subjects design that includes only the effect of the YEAR<br />

within-subjects factor. Because YEAR is the only within-subjects factor specified, this is<br />

the default design, and WSDESIGN could have been omitted.<br />

• DESIGN specifies a between-subjects design that includes only the effect of the GROUP<br />

between-subjects factor. This subcommand could have been omitted.<br />

MANOVA Variable List<br />

The list of dependent variables, factors, and covariates must be specified first.<br />

• WSFACTORS determines how the dependent variables on the MANOVA variable list will<br />

be interpreted.<br />

• The number of dependent variables on the MANOVA variable list must be a multiple of the<br />

number of cells in the within-subjects design. If there are six cells in the within-subjects<br />

design, each group of six dependent variables represents a single within-subjects variable<br />

that has been measured in each of the six cells.<br />

• Normally, the number of dependent variables should equal the number of cells in the<br />

within-subjects design multiplied by the number of variables named on the MEASURE<br />

subcommand (if one is used). If you have more groups of dependent variables than are<br />

accounted for by the MEASURE subcommand, MANOVA will choose variable names to<br />

label the output, which may be difficult to interpret.<br />

• Covariates are specified after the keyword WITH. You can specify either varying covariates<br />

or constant covariates, or both. Varying covariates, similar to dependent variables<br />

in a repeated measures analysis, represent measurements of the same variable (or variables)<br />

at different times while constant covariates represent variables whose values<br />

remain the same at each within-subjects measurement.<br />

• If you use varying covariates, the number of covariates specified must be an integer<br />

multiple of the number of dependent variables.

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