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SPSS® 12.0 Command Syntax Reference

SPSS® 12.0 Command Syntax Reference

SPSS® 12.0 Command Syntax Reference

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LOGISTIC REGRESSION 813<br />

• POUT requires that the probability of the statistic used to test whether a variable should<br />

remain in the model be smaller than 0.05. This is more stringent than the default value of<br />

0.1.<br />

• PIN requires that the probability of the score statistic used to test whether a variable should<br />

be included be smaller than 0.01. This makes it more difficult for variables to be included<br />

in the model than the default value of 0.05.<br />

CLASSPLOT Subcommand<br />

CLASSPLOT generates a classification plot of the actual and predicted values of the dichotomous<br />

dependent variable at each step.<br />

• Keyword CLASSPLOT is the only specification.<br />

• If CLASSPLOT is not specified, plots are not generated.<br />

Example<br />

LOGISTIC REGRESSION PROMOTED WITH JOBTIME RACE<br />

/CATEGORICAL RACE<br />

/CLASSPLOT.<br />

• A logistic regression model is constructed for the dichotomous dependent variable<br />

PROMOTED and the independent variables JOBTIME and RACE.<br />

• CLASSPLOT produces a classification plot for the dependent variable PROMOTED. The<br />

vertical axis of the plot is the frequency of the variable PROMOTED. The horizontal axis<br />

is the predicted probability of membership in the second of the two levels of PROMOTED.<br />

CASEWISE Subcommand<br />

CASEWISE produces a casewise listing of the values of the temporary variables created by<br />

LOGISTIC REGRESSION.<br />

The following keywords are available for specifying temporary variables (see Fox, 1984).<br />

When CASEWISE is specified by itself, the default lists PRED, PGROUP, RESID, and ZRESID.<br />

If a list of variable names is given, only those named temporary variables are displayed.<br />

PRED Predicted probability. For each case, the predicted probability of having the<br />

second of the two values of the dichotomous dependent variable.<br />

PGROUP Predicted group. The group to which a case is assigned based on the predicted<br />

probability.<br />

RESID Difference between observed and predicted probabilities.<br />

DEV Deviance values. For each case, a log-likelihood-ratio statistic, which measures<br />

how well the model fits the case, is computed.<br />

LRESID Logit residual. Residual divided by the product of PRED and 1–PRED.<br />

SRESID Studentized residual.

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