SPSS® 12.0 Command Syntax Reference

1378 RELIABILITY
• This example analyzes a scale (labeled ALL in the display output) that includes all 10
items.
• Because there is no SUMMARY subcommand, no summary statistics are displayed.
VARIABLES Subcommand
VARIABLES specifies the variables to be used in the analysis. Only numeric variables can be
used.
• VARIABLES is required and must be specified first.
• You can use keyword ALL to refer to all user-defined variables in the working data file.
SCALE Subcommand
SCALE defines a scale for analysis, providing a label for the scale and specifying its component
variables. If SCALE is omitted, all variables named on VARIABLES are used, and the label
for the scale is ALL.
• The label is specified in parentheses after SCALE. It can have a maximum of eight characters
and can use only the letters A to Z and the numerals 0 to 9.
• RELIABILITY does not add any new variables to the working data file. The label is used
only to identify the output. If the analysis is satisfactory, use COMPUTE to create a new
variable containing the sum of the component items.
• Variables named on SCALE must have been named on the VARIABLES subcommand. Use
the keyword ALL to refer to all variables named on the VARIABLES subcommand.
Example
RELIABILITY VARIABLES = ITEM1 TO ITEM20
/SCALE (A) = ITEM1 TO ITEM10.
RELIABILITY VARIABLES = ITEM1 TO ITEM20
/SCALE (B) = ITEM1 TO ITEM20.
• Analyses for scales A and B both only use cases that have complete data for items 1
through 20.
MODEL Subcommand
MODEL specifies the type of reliability analysis for the scale named on the SCALE subcommand.
ALPHA Cronbach’s α. Standardized item α is displayed. This is the default.
SPLIT [(n)] Split-half coefficients. You can specify a number in parentheses to
indicate how many items should be in the second half. For example,
MODEL SPLIT (6) uses the last six variables for the second half and all
others for the first. By default, each half has an equal number of items,
with the odd item, if any, going to the first half.