The column means test is not suitable for all tables. When you request the test on a table that is structurally unsuitable, UNICOM Intelligence Professional simply skips the test. It is up to you to make sure that the data in the table is generally suitable for testing, that the sample size is suitable, etc.

This test is unsuitable for running on lower level data when you are working with hierarchical data a hierarchical view of the data. See Hierarchical data for more information.

It is possible to run this test on grids, provided that the test is carried out on a grid table structured in the format:

This test is unsuitable for running on grid tables in the format:

This test is unsuitable for running when weighting is applied to individual columns or rows.

UNICOM Intelligence Professional can perform this test only if there is a mean row on the side axis. The mean row must be formed from a mean element. This can be a built-in mean or a mean added to the variable using the Edit Variable window. This can be a built-in mean element or a mean element added to the axis expression. This can be a built-in mean element or a mean element added to the axis expression. See Special elements.

The test does not test mean values created using the Mean cell contents option.

For each mean row, the test compares pairs of columns that are formed from variable categories. UNICOM Intelligence Professional does not compare columns that are formed from non-category elements or columns in which the number of cases contributing to the mean is zero. The test cannot be performed on tables that contain more than 52 category columns if you request one significance level, or 26 category columns if you request two significance levels, and it needs a minimum of two category columns.

If a column means test is included in the metadata for a variable, the test is performed only if the variable is added as a single variable. If it is nested or concatenated with other variables, the built-in test is ignored to prevent possible inconsistencies in the results, and you must explicitly specify a column means test for the whole axis.

If there is nesting on the top axis, the test is performed separately for each set of columns that are formed from the categories of the innermost child variables. This means that the innermost child variables must have at least two categories. Nesting on the side axis does not change the test--each mean row is always tested.

If there is concatenation on the top axis, the test is performed separately for each set of columns that are formed from the categories of a concatenated variable. Concatenation on the side axis does not change the test--each mean row is always tested.

If any of the variables on the top axis has more than one base element, the test will be performed separately for the columns formed from the categories before and after each base.

This test relies on a central limit theorem approximation to the normal distribution. This means that a large sample (generally at least 30 cases) is required if the data is not distributed normally.

However, when the data is distributed normally, a large sample is not necessary. UNICOM Intelligence Professional checks for small sample sizes, and does not carry out the test on columns with a base below 30. You can change the minimum sample size if required, using the MinBase property, by entering a new value in the Minimum Base field in the Statistics tab of the Table Properties dialog box, by entering a new value in the Minimum Base field in the Preferences tab.

When there is a multiple response variable on the top axis, UNICOM Intelligence Professional performs the overlap adjustment.

The column means test is performed on a table whether or not the table contains elements that are excluded from the base using IncludeInBase=False. The calculation includes rows and columns corresponding to the excluded elements.

Each axis can be derived from either an axis expression or an MDM variable. When an axis is derived from an axis expression, TOM will honor the MaxResponses property. When the MaxResponses value is greater or equal to 2, TOM regards the axis as overlapped. Considering that the MaxResponses default value is 2, each axis is in an overlap state by default.

When an axis is derived from an MDM variable, TOM will honor the variable's EffectiveMaxValue property. When the EffectiveMaxValue value is greater or equal to 2, TOM regards the axis as overlapped.

When there are any sub-axis that are overlapped for a table's side and top, TOM regards the side or top as overlapped.

When both the side and top are overlapped for a table, and UseGridOverlapFormula is true, the grid overlap formula is applied to the table. The normal overlap formula is applied when the table's top is overlapped, otherwise the standard formula is used.