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10 Tabulation of the data and prediction from the model 160should only be omitted from the hyper-table when they only appear in randomterms. Whether terms derived from these variables should be used when formingpredictions depends on the application and aim of prediction.The main difference in this prediction process compared to that described by Laneand Nelder (1982) is the choice of whether to include or exclude model terms whenforming predictions. In linear models, since all terms are fixed, terms not in theclassify set must be in the averaging set.Predict syntaxThe first step is to specify the classify set ofexplanatory variables after the predict directive.The predict statement(s) may appearimmediately after the model line (before or afterany tabulate statements) or after the Rand G structure lines. The syntax ispredict factors [qualifiers]NIN Alliance trial 1989variety !A.column 11nin89.asd !skip 1yield ∼ mu variety !r replpredict variety0 0 1repl 1repl 0 IDV 0.1• predict must be the first element of thepredict statement, commencing in column 1 in upper or lower case,• factors is a list of the variables defining a multiway table to be predicted; eachvariable may be followed by a list of specific values to be predicted,• the qualifiers, listed in Table 10.1, instruct ASReml to modify the predictionsin some way,• a predict statement may be continued on subsequent lines by terminating thecurrent line with a comma,• several predict statements may be specified.ASReml parses the predict statement before fitting the model. If any syntaxproblems are encountered, these are reported in the .pvs file after which thestatement is ignored: the job is completed as if the erroneous prediction statementdid not exist. The predictions are formed as an extra process in the final iterationand are reported to the .pvs file. Consequently, aborting a run by creating theABORTASR.NOW file (see page 65) will cause any predict statements to be ignored.By default, factors are predicted at each level, simple covariates are predictedat their overall mean and covariates used as a basis for splines or orthogonal