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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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1582 T-TEST<br />

degrees of freedom, and two-tailed probabilities, as well as the mean, standard deviation,<br />

standard error, and count for each group or variable.<br />

• To request a one-sample test, use the TESTVAL and VARIABLES subcommands. The output<br />

includes a One-Sample Statistics table showing univariate statistics and a One-Sample<br />

Test table showing the test value, the difference between the sample mean and the test<br />

value and two-tailed probability level.<br />

• To request an independent-samples test, use the GROUPS and VARIABLES subcommands.<br />

The output includes a Group Statistics table showing summary statistics by group for<br />

each dependent variable and an Independent-Samples Test table showing both pooledand<br />

separate-variance estimates, along with the F value used to test homogeneity of variance<br />

and its probability. The two-tailed probability is displayed for the t value.<br />

• To request a paired-samples test, use the PAIRS subcommand. The output includes a Paired<br />

Statistics table showing univariate statistics by pairs, a Paired Samples Correlations table<br />

showing correlation coefficients and two-tailed probability level for a test of the coefficient<br />

for each pair, and a Paired Samples Test table showing the paired differences between<br />

the means and two-tailed probability levels for a test of the differences.<br />

Subcommand Order<br />

Subcommands can be named in any order.<br />

Operations<br />

• If a variable specified on GROUPS is a long string, only the short-string portion is used to<br />

identify groups in the analysis.<br />

• Probability levels are two-tailed. To obtain the one-tailed probability, divide the twotailed<br />

probability by 2.<br />

Limitations<br />

Example<br />

Example<br />

• Maximum 1 TESTVAL and 1 VARIABLES subcommand per one-sample t test.<br />

• Maximum 1 GROUPS and 1 VARIABLES subcommand per independent-samples t test.<br />

T TEST TESTVAL 28000 /VARIABLES=CHISAL LASAL NYSAL.<br />

• This one-sample t test compares the means of CHISAL, LASAL, and NYSAL each with the<br />

standard value (28000).<br />

T-TEST GROUPS=WORLD(1,3) /VARIABLES=NTCPRI NTCSAL NTCPUR.

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