TEST Subcommand (PLUM command)

The TEST subcommand allows you to customize your hypothesis tests by directly specifying null hypotheses as linear combinations of parameters.

  • TEST is offered only through syntax.
  • Multiple TEST subcommands are allowed. Each is handled independently.
  • The basic format of the TEST subcommand is an optional list of values enclosed in a pair of parentheses, an optional label in quotes, an effect name or the keyword ALL, and a list of values.
  • To specify the coefficient for the intercept, use the keyword INTERCEPT. The number of values after INTERCEPT must be equal to the number of response categories minus 1.
  • When multiple linear combinations are specified within the same TEST subcommand, a semicolon terminates each linear combination, except the last one.
  • The linear combinations are separately tested for each category of the dependent variable and then simultaneously tested for all the categories.
  • If specified, the value list that immediately follows the subcommand name is the constant that the linear combinations are equated to under the null hypotheses. If this value list is omitted, the constants are assumed to be all zeros.
  • The optional label is a string with a maximum length of 255 bytes. Only one label per TEST subcommand can be specified.
  • Only valid effects appearing or implied on the LOCATION or the SCALE subcommands can be specified in a linear combination. If an effect appears in both subcommands, then enter the effect only once on the TEST subcommand.
  • To specify coefficient for the intercept, use the keyword INTERCEPT. Only one value is expected to follow INTERCEPT.
  • The number of values following an effect name must equal the number of parameters (including the redundant ones) corresponding to that effect. For example, if the effect A*B takes up six parameters, then exactly six values must follow A*B.
  • A number can be specified as a fraction with a positive denominator. For example, 1/3 or –1/3 are valid, but 1/–3 is invalid.
  • When ALL is specified, only a list of values can follow. The number of values must equal the combined number of LOCATION and SCALE parameters (including the redundant ones).
  • Effects appearing or implied on the LOCATION or the SCALE subcommands but not specified on the TEST are assumed to take the value 0 for all their parameters.
  • Effect names and the ALL keywords are mutually exclusive within a single TEST subcommand.
  • If ALL is specified for the first row in a TEST matrix, then all subsequent rows should begin with the ALL keyword.
  • If effects are specified for the first row in a TEST matrix, then all subsequent rows should use effect name (thus ALL is not allowed).

Example

PLUM
  chist  BY housng
  /CRITERIA = CIN(95) DELTA(0) LCONVERGE(0) MXITER(100) MXSTEP(5)
              PCONVERGE(1.0E-6) SINGULAR(1.0E-8)
  /LINK = CLOGLOG
  /PRINT = CELLINFO CORB COVB FIT HISTORY(1) PARAMETER 
           SUMMARY TPARALLEL 
  /TEST(0 0) =  ALL 1 -1 0 0 0 0 0;
                ALL 0 0 1 -1 0 0 0.
  • There are a total of seven parameter coefficients in the model; four for the thresholds, and three for the factor housng. TEST specifies two separate tests: one in which the first and second thresholds are tested for equality, and one in which the third and fourth thresholds are tested for equality.