All tests, except the Paired Preference test, compare columns of data; the Paired Preference test compares rows.

Quantum normally includes all basic elements in a test. Basic elements are elements created by n01, n15, n10 or n11 statements or their counterparts on col, val, bit or fld statements, and elements created by m statements which manipulate basic elements. All other types of element are ignored.

If you do not want to test all basic elements in the axis you can either select the ones you do want to test or reject those you do not. To exclude elements from a test, place the keyword notstat on the statements that create those elements. For example:

If you want to exclude more elements than you want to include, an alternative is to place notstat on the l statement to set exclusion as the default for the axis, and then to flag the elements you want to test with tstat. Here is the previous example in reverse:

tstat and notstat are also valid on a, flt, sectbeg and tab statements to request or suppress T-tests for all tables at the given level. If you use notstat on a tab statement, for example, Quantum will ignore tstat statements under the tab statement as well as tstat options in the column axis of that table. This can be useful when you want to produce several tables using the same column axis but only want the T-tests in certain of those tables. You define the axis with the necessary statements and options for the T-tests, and then request or suppress the tests using tstat or notstat on the tab statement.