Shared Statistical Concepts


Effect Operators

Table 4.6 summarizes the operators that are available for selecting and constructing effects. These operators are discussed in the following sections.

Table 4.6: Available Effect Operators

Operator

Example

Description

Interaction

A*B

Crosses the levels of the effects

Nesting

A(B)

Nests A levels within B levels

Bar operator

A | B | C

Specifies all interactions

At sign operator

A | B | C@2

Reduces interactions in bar effects

Dash operator

A1-A10

Specifies sequentially numbered variables

Colon operator

A:

Specifies variables with common prefix

Double dash operator

A- -C

Specifies sequential variables in data set order